tnew venti library. - plan9port - [fork] Plan 9 from user space
(HTM) git clone git://src.adamsgaard.dk/plan9port
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---
(DIR) commit 056fe1ba7fa0b70f871dfb9005b24eb8e4cc230b
(DIR) parent 9df487d720a59bf8cb0dc4ccffc30ad8eb48256a
(HTM) Author: rsc <devnull@localhost>
Date: Sun, 23 Nov 2003 18:19:58 +0000
new venti library.
Diffstat:
A src/libventi/cache.c | 560 +++++++++++++++++++++++++++++++
A src/libventi/client.c | 151 +++++++++++++++++++++++++++++++
A src/libventi/conn.c | 36 +++++++++++++++++++++++++++++++
A src/libventi/cvt.h | 15 +++++++++++++++
A src/libventi/debug.c | 17 +++++++++++++++++
A src/libventi/dial.c | 21 +++++++++++++++++++++
A src/libventi/dtype.c | 78 +++++++++++++++++++++++++++++++
A src/libventi/entry.c | 85 +++++++++++++++++++++++++++++++
A src/libventi/fcall.c | 230 +++++++++++++++++++++++++++++++
A src/libventi/fcallfmt.c | 55 +++++++++++++++++++++++++++++++
A src/libventi/file.c | 1264 +++++++++++++++++++++++++++++++
A src/libventi/hangup.c | 22 ++++++++++++++++++++++
A src/libventi/mem.c | 87 +++++++++++++++++++++++++++++++
A src/libventi/mkfile | 42 +++++++++++++++++++++++++++++++
A src/libventi/packet.c | 941 +++++++++++++++++++++++++++++++
A src/libventi/queue.c | 103 +++++++++++++++++++++++++++++++
A src/libventi/queue.h | 6 ++++++
A src/libventi/root.c | 67 +++++++++++++++++++++++++++++++
A src/libventi/rpc.c | 155 +++++++++++++++++++++++++++++++
A src/libventi/scorefmt.c | 18 ++++++++++++++++++
A src/libventi/send.c | 212 ++++++++++++++++++++++++++++++
A src/libventi/server.c | 172 ++++++++++++++++++++++++++++++
A src/libventi/srvhello.c | 50 +++++++++++++++++++++++++++++++
A src/libventi/strdup.c | 18 ++++++++++++++++++
A src/libventi/string.c | 50 +++++++++++++++++++++++++++++++
A src/libventi/version.c | 115 +++++++++++++++++++++++++++++++
A src/libventi/zero.c | 55 +++++++++++++++++++++++++++++++
A src/libventi/zeroscore.c | 10 ++++++++++
28 files changed, 4635 insertions(+), 0 deletions(-)
---
(DIR) diff --git a/src/libventi/cache.c b/src/libventi/cache.c
t@@ -0,0 +1,560 @@
+/*
+ * Memory-only VtBlock cache.
+ *
+ * The cached Venti blocks are in the hash chains.
+ * The cached local blocks are only in the blocks array.
+ * The free blocks are in the heap, which is supposed to
+ * be indexed by second-to-last use but actually
+ * appears to be last use.
+ */
+
+#include <u.h>
+#include <libc.h>
+#include <venti.h>
+
+int nread, ncopy, nwrite;
+
+enum {
+ BioLocal = 1,
+ BioVenti,
+ BioReading,
+ BioWriting,
+ BioEmpty,
+ BioVentiError,
+};
+enum {
+ BadHeap = ~0,
+};
+struct VtCache
+{
+ QLock lk;
+ VtConn *z;
+ u32int blocksize;
+ u32int now; /* ticks for usage time stamps */
+ VtBlock **hash; /* hash table for finding addresses */
+ int nhash;
+ VtBlock **heap; /* heap for finding victims */
+ int nheap;
+ VtBlock *block; /* all allocated blocks */
+ int nblock;
+ uchar *mem; /* memory for all blocks and data */
+ int mode;
+};
+
+static void cachecheck(VtCache*);
+
+VtCache*
+vtcachealloc(VtConn *z, int blocksize, ulong nblock, int mode)
+{
+ uchar *p;
+ VtCache *c;
+ int i;
+ VtBlock *b;
+
+ c = vtmallocz(sizeof(VtCache));
+
+ c->z = z;
+ c->blocksize = (blocksize + 127) & ~127;
+ c->nblock = nblock;
+
+ c->nhash = nblock;
+ c->hash = vtmallocz(nblock*sizeof(VtBlock*));
+ c->heap = vtmallocz(nblock*sizeof(VtBlock*));
+ c->block = vtmallocz(nblock*sizeof(VtBlock));
+ c->mem = vtmallocz(nblock*c->blocksize);
+ c->mode = mode;
+
+ p = c->mem;
+ for(i=0; i<nblock; i++){
+ b = &c->block[i];
+ b->addr = NilBlock;
+ b->c = c;
+ b->data = p;
+ b->heap = i;
+ c->heap[i] = b;
+ p += c->blocksize;
+ }
+ c->nheap = nblock;
+ cachecheck(c);
+ return c;
+}
+
+void
+vtcachefree(VtCache *c)
+{
+ int i;
+
+ qlock(&c->lk);
+
+ cachecheck(c);
+ for(i=0; i<c->nblock; i++)
+ assert(c->block[i].ref == 0);
+
+ vtfree(c->hash);
+ vtfree(c->heap);
+ vtfree(c->block);
+ vtfree(c->mem);
+ vtfree(c);
+}
+
+static void
+vtcachedump(VtCache *c)
+{
+ int i;
+ VtBlock *b;
+
+ for(i=0; i<c->nblock; i++){
+ b = &c->block[i];
+ print("cache block %d: type %d score %V iostate %d addr %d ref %d nlock %d\n",
+ i, b->type, b->score, b->iostate, b->addr, b->ref, b->nlock);
+ }
+}
+
+static void
+cachecheck(VtCache *c)
+{
+ u32int size, now;
+ int i, k, refed;
+ VtBlock *b;
+
+ size = c->blocksize;
+ now = c->now;
+
+ for(i = 0; i < c->nheap; i++){
+ if(c->heap[i]->heap != i)
+ sysfatal("mis-heaped at %d: %d", i, c->heap[i]->heap);
+ if(i > 0 && c->heap[(i - 1) >> 1]->used - now > c->heap[i]->used - now)
+ sysfatal("bad heap ordering");
+ k = (i << 1) + 1;
+ if(k < c->nheap && c->heap[i]->used - now > c->heap[k]->used - now)
+ sysfatal("bad heap ordering");
+ k++;
+ if(k < c->nheap && c->heap[i]->used - now > c->heap[k]->used - now)
+ sysfatal("bad heap ordering");
+ }
+
+ refed = 0;
+ for(i = 0; i < c->nblock; i++){
+ b = &c->block[i];
+ if(b->data != &c->mem[i * size])
+ sysfatal("mis-blocked at %d", i);
+ if(b->ref && b->heap == BadHeap)
+ refed++;
+ else if(b->addr != NilBlock)
+ refed++;
+ }
+if(c->nheap + refed != c->nblock){
+fprint(2, "cachecheck: nheap %d refed %d nblocks %d\n", c->nheap, refed, c->nblock);
+//vtcachedump(c);
+}
+ assert(c->nheap + refed == c->nblock);
+ refed = 0;
+ for(i = 0; i < c->nblock; i++){
+ b = &c->block[i];
+ if(b->ref){
+if(1)fprint(2, "a=%ud %V ref=%d\n", b->addr, b->score, b->ref);
+ refed++;
+ }
+ }
+if(refed > 0)fprint(2, "cachecheck: in used %d\n", refed);
+}
+
+static int
+upheap(int i, VtBlock *b)
+{
+ VtBlock *bb;
+ u32int now;
+ int p;
+ VtCache *c;
+
+ c = b->c;
+ now = c->now;
+ for(; i != 0; i = p){
+ p = (i - 1) >> 1;
+ bb = c->heap[p];
+ if(b->used - now >= bb->used - now)
+ break;
+ c->heap[i] = bb;
+ bb->heap = i;
+ }
+ c->heap[i] = b;
+ b->heap = i;
+
+ return i;
+}
+
+static int
+downheap(int i, VtBlock *b)
+{
+ VtBlock *bb;
+ u32int now;
+ int k;
+ VtCache *c;
+
+ c = b->c;
+ now = c->now;
+ for(; ; i = k){
+ k = (i << 1) + 1;
+ if(k >= c->nheap)
+ break;
+ if(k + 1 < c->nheap && c->heap[k]->used - now > c->heap[k + 1]->used - now)
+ k++;
+ bb = c->heap[k];
+ if(b->used - now <= bb->used - now)
+ break;
+ c->heap[i] = bb;
+ bb->heap = i;
+ }
+ c->heap[i] = b;
+ b->heap = i;
+ return i;
+}
+
+/*
+ * Delete a block from the heap.
+ * Called with c->lk held.
+ */
+static void
+heapdel(VtBlock *b)
+{
+ int i, si;
+ VtCache *c;
+
+ c = b->c;
+
+ si = b->heap;
+ if(si == BadHeap)
+ return;
+ b->heap = BadHeap;
+ c->nheap--;
+ if(si == c->nheap)
+ return;
+ b = c->heap[c->nheap];
+ i = upheap(si, b);
+ if(i == si)
+ downheap(i, b);
+}
+
+/*
+ * Insert a block into the heap.
+ * Called with c->lk held.
+ */
+static void
+heapins(VtBlock *b)
+{
+ assert(b->heap == BadHeap);
+ upheap(b->c->nheap++, b);
+}
+
+/*
+ * locate the vtBlock with the oldest second to last use.
+ * remove it from the heap, and fix up the heap.
+ */
+/* called with c->lk held */
+static VtBlock*
+vtcachebumpblock(VtCache *c)
+{
+ VtBlock *b;
+
+ /*
+ * locate the vtBlock with the oldest second to last use.
+ * remove it from the heap, and fix up the heap.
+ */
+ if(c->nheap == 0){
+ vtcachedump(c);
+abort();
+ sysfatal("vtcachebumpblock: no free blocks in vtCache");
+ }
+ b = c->heap[0];
+ heapdel(b);
+
+ assert(b->heap == BadHeap);
+ assert(b->ref == 0);
+
+ /*
+ * unchain the vtBlock from hash chain if any
+ */
+ if(b->prev){
+ *(b->prev) = b->next;
+ if(b->next)
+ b->next->prev = b->prev;
+ b->prev = nil;
+ }
+
+
+if(0)fprint(2, "droping %x:%V\n", b->addr, b->score);
+ /* set vtBlock to a reasonable state */
+ b->ref = 1;
+ b->iostate = BioEmpty;
+ return b;
+}
+
+/*
+ * fetch a local block from the memory cache.
+ * if it's not there, load it, bumping some other Block.
+ * if we're out of free blocks, we're screwed.
+ */
+VtBlock*
+vtcachelocal(VtCache *c, u32int addr, int type)
+{
+ VtBlock *b;
+
+ if(addr >= c->nblock)
+ sysfatal("vtcachelocal: asked for block #%ud; only %d blocks\n",
+ addr, c->nblock);
+
+ b = &c->block[addr];
+ if(b->addr == NilBlock || b->iostate != BioLocal)
+{
+abort();
+ sysfatal("vtcachelocal: block is not local");
+}
+
+ if(b->type != type)
+{
+print("%d != %d\n", b->type, type);
+abort();
+ sysfatal("vtcachelocal: block has wrong type %d != %d", b->type, type);
+}
+
+ qlock(&c->lk);
+ b->ref++;
+ qunlock(&c->lk);
+
+ qlock(&b->lk);
+ b->nlock = 1;
+ return b;
+}
+
+VtBlock*
+vtcacheallocblock(VtCache *c, int type)
+{
+ VtBlock *b;
+
+if(type >= VtMaxType)
+ abort();
+
+ qlock(&c->lk);
+ b = vtcachebumpblock(c);
+ b->iostate = BioLocal;
+ b->type = type;
+ b->addr = b - c->block;
+ vtzeroextend(type, b->data, 0, c->blocksize);
+ vtlocaltoglobal(b->addr, b->score);
+ qunlock(&c->lk);
+
+ qlock(&b->lk);
+ b->nlock = 1;
+
+ return b;
+}
+
+/*
+ * fetch a global (Venti) block from the memory cache.
+ * if it's not there, load it, bumping some other block.
+ */
+VtBlock*
+vtcacheglobal(VtCache *c, uchar score[VtScoreSize], int type)
+{
+ VtBlock *b;
+ ulong h;
+ int n;
+ u32int addr;
+
+ addr = vtglobaltolocal(score);
+ if(addr != NilBlock)
+ return vtcachelocal(c, addr, type);
+
+ h = (u32int)(score[0]|(score[1]<<8)|(score[2]<<16)|(score[3]<<24)) % c->nhash;
+
+ /*
+ * look for the block in the cache
+ */
+ qlock(&c->lk);
+ for(b = c->hash[h]; b != nil; b = b->next){
+ if(b->addr != NilBlock || memcmp(b->score, score, VtScoreSize) != 0 || b->type != type)
+ continue;
+ heapdel(b);
+ b->ref++;
+ qunlock(&c->lk);
+ qlock(&b->lk);
+ b->nlock = 1;
+ return b;
+ }
+
+ /*
+ * not found
+ */
+ b = vtcachebumpblock(c);
+ b->addr = NilBlock;
+ b->type = type;
+ memmove(b->score, score, VtScoreSize);
+ /* chain onto correct hash */
+ b->next = c->hash[h];
+ c->hash[h] = b;
+ if(b->next != nil)
+ b->next->prev = &b->next;
+ b->prev = &c->hash[h];
+
+ /*
+ * Lock b before unlocking c, so that others wait while we read.
+ *
+ * You might think there is a race between this qlock(b) before qunlock(c)
+ * and the qlock(c) while holding a qlock(b) in vtblockwrite. However,
+ * the block here can never be the block in a vtblockwrite, so we're safe.
+ * We're certainly living on the edge.
+ */
+ qlock(&b->lk);
+ b->nlock = 1;
+ qunlock(&c->lk);
+
+ n = vtread(c->z, score, type, b->data, c->blocksize);
+ if(n < 0){
+fprint(2, "vtread: %r\n");
+ b->iostate = BioVentiError;
+ vtblockput(b);
+ return nil;
+ }
+ vtzeroextend(type, b->data, n, c->blocksize);
+ b->iostate = BioVenti;
+ b->nlock = 1;
+ b->decrypted = 0;
+ return b;
+}
+
+/*
+ * The thread that has locked b may refer to it by
+ * multiple names. Nlock counts the number of
+ * references the locking thread holds. It will call
+ * vtblockput once per reference.
+ */
+void
+vtblockduplock(VtBlock *b)
+{
+ assert(b->nlock > 0);
+ b->nlock++;
+}
+
+/*
+ * we're done with the block.
+ * unlock it. can't use it after calling this.
+ */
+void
+vtblockput(VtBlock* b)
+{
+ VtCache *c;
+
+ if(b == nil)
+ return;
+
+if(0)fprint(2, "vtblockput: %d: %x %d %d\n", getpid(), b->addr, c->nheap, b->iostate);
+
+ if(--b->nlock > 0)
+ return;
+
+ /*
+ * b->nlock should probably stay at zero while
+ * the vtBlock is unlocked, but diskThread and vtSleep
+ * conspire to assume that they can just qlock(&b->lk); vtblockput(b),
+ * so we have to keep b->nlock set to 1 even
+ * when the vtBlock is unlocked.
+ */
+ assert(b->nlock == 0);
+ b->nlock = 1;
+
+ qunlock(&b->lk);
+ c = b->c;
+ qlock(&c->lk);
+
+ if(--b->ref > 0){
+ qunlock(&c->lk);
+ return;
+ }
+
+ assert(b->ref == 0);
+ switch(b->iostate){
+ case BioVenti:
+//if(b->addr != NilBlock) print("blockput %d\n", b->addr);
+ b->used = c->now++;
+ case BioVentiError:
+ heapins(b);
+ break;
+ case BioLocal:
+ break;
+ }
+ qunlock(&c->lk);
+}
+
+int
+vtblockwrite(VtBlock *b)
+{
+ uchar score[VtScoreSize];
+ VtCache *c;
+ uint h;
+ int n;
+
+ if(b->iostate != BioLocal){
+ abort();
+ sysfatal("vtBlockWrite: not a local block");
+ }
+
+ c = b->c;
+ n = vtzerotruncate(b->type, b->data, c->blocksize);
+ if(vtwrite(c->z, score, b->type, b->data, n) < 0)
+ return -1;
+
+ memmove(b->score, score, VtScoreSize);
+
+ qlock(&c->lk);
+ b->iostate = BioVenti;
+ h = (u32int)(score[0]|(score[1]<<8)|(score[2]<<16)|(score[3]<<24)) % c->nhash;
+ b->next = c->hash[h];
+ c->hash[h] = b;
+ if(b->next != nil)
+ b->next->prev = &b->next;
+ b->prev = &c->hash[h];
+ qunlock(&c->lk);
+ return 0;
+}
+
+uint
+vtcacheblocksize(VtCache *c)
+{
+ return c->blocksize;
+}
+
+VtBlock*
+vtblockcopy(VtBlock *b)
+{
+ VtBlock *bb;
+
+ncopy++;
+ bb = vtcacheallocblock(b->c, b->type);
+ if(bb == nil){
+ vtblockput(b);
+ return nil;
+ }
+ memmove(bb->data, b->data, b->c->blocksize);
+ vtblockput(b);
+ return bb;
+}
+
+void
+vtlocaltoglobal(u32int addr, uchar score[VtScoreSize])
+{
+ memset(score, 0, 16);
+ score[16] = addr>>24;
+ score[17] = addr>>16;
+ score[18] = addr>>8;
+ score[19] = addr;
+}
+
+
+u32int
+vtglobaltolocal(uchar score[VtScoreSize])
+{
+ static uchar zero[16];
+ if(memcmp(score, zero, 16) != 0)
+ return NilBlock;
+ return (score[16]<<24)|(score[17]<<16)|(score[18]<<8)|score[19];
+}
(DIR) diff --git a/src/libventi/client.c b/src/libventi/client.c
t@@ -0,0 +1,151 @@
+#include <u.h>
+#include <libc.h>
+#include <venti.h>
+
+static int
+vtfcallrpc(VtConn *z, VtFcall *ou, VtFcall *in)
+{
+ Packet *p;
+
+ p = vtfcallpack(ou);
+ if(p == nil)
+ return -1;
+ if((p = vtrpc(z, p)) == nil)
+ return -1;
+ if(vtfcallunpack(in, p) < 0){
+ packetfree(p);
+ return -1;
+ }
+ if(in->type == VtRerror){
+ werrstr(in->error);
+ vtfcallclear(in);
+ packetfree(p);
+ return -1;
+ }
+ if(in->type != ou->type+1){
+ werrstr("type mismatch: sent %c%d got %c%d",
+ "TR"[ou->type&1], ou->type>>1,
+ "TR"[in->type&1], in->type>>1);
+ vtfcallclear(in);
+ packetfree(p);
+ return -1;
+ }
+ packetfree(p);
+ return 0;
+}
+
+int
+vthello(VtConn *z)
+{
+ VtFcall tx, rx;
+
+ memset(&tx, 0, sizeof tx);
+ tx.type = VtThello;
+ tx.version = z->version;
+ tx.uid = z->uid;
+ if(tx.uid == nil)
+ tx.uid = "anonymous";
+ if(vtfcallrpc(z, &tx, &rx) < 0)
+ return -1;
+ z->sid = rx.sid;
+ rx.sid = 0;
+ vtfcallclear(&rx);
+ return 0;
+}
+
+Packet*
+vtreadpacket(VtConn *z, uchar score[VtScoreSize], uint type, int n)
+{
+ VtFcall tx, rx;
+
+ memset(&tx, 0, sizeof tx);
+ tx.type = VtTread;
+ tx.dtype = type;
+ tx.count = n;
+ memmove(tx.score, score, VtScoreSize);
+ if(vtfcallrpc(z, &tx, &rx) < 0)
+ return nil;
+ if(packetsize(rx.data) > n){
+ werrstr("read returned too much data");
+ packetfree(rx.data);
+ return nil;
+ }
+ packetsha1(rx.data, tx.score);
+ if(memcmp(score, tx.score, VtScoreSize) != 0){
+ werrstr("read asked for %V got %V", score, tx.score);
+ packetfree(rx.data);
+ return nil;
+ }
+
+ return rx.data;
+}
+
+int
+vtread(VtConn *z, uchar score[VtScoreSize], uint type, uchar *buf, int n)
+{
+ int nn;
+ Packet *p;
+
+ if((p = vtreadpacket(z, score, type, n)) == nil)
+ return -1;
+ nn = packetsize(p);
+ if(packetconsume(p, buf, nn) < 0)
+ abort();
+ return nn;
+}
+
+int
+vtwritepacket(VtConn *z, uchar score[VtScoreSize], uint type, Packet *p)
+{
+ VtFcall tx, rx;
+
+ tx.type = VtTwrite;
+ tx.dtype = type;
+ tx.data = p;
+ packetsha1(p, score);
+ if(vtfcallrpc(z, &tx, &rx) < 0)
+ return -1;
+ if(memcmp(score, rx.score, VtScoreSize) != 0){
+ werrstr("sha1 hash mismatch: want %V got %V", score, rx.score);
+ return -1;
+ }
+ return 0;
+}
+
+int
+vtwrite(VtConn *z, uchar score[VtScoreSize], uint type, uchar *buf, int n)
+{
+ Packet *p;
+
+ p = packetforeign(buf, n, nil, nil);
+ return vtwritepacket(z, score, type, p);
+}
+
+int
+vtsync(VtConn *z)
+{
+ VtFcall tx, rx;
+
+ tx.type = VtTsync;
+ return vtfcallrpc(z, &tx, &rx);
+}
+
+int
+vtping(VtConn *z)
+{
+ VtFcall tx, rx;
+
+ tx.type = VtTping;
+ return vtfcallrpc(z, &tx, &rx);
+}
+
+int
+vtconnect(VtConn *z)
+{
+ if(vtversion(z) < 0)
+ return -1;
+ if(vthello(z) < 0)
+ return -1;
+ return 0;
+}
+
(DIR) diff --git a/src/libventi/conn.c b/src/libventi/conn.c
t@@ -0,0 +1,36 @@
+#include <u.h>
+#include <libc.h>
+#include <venti.h>
+#include "queue.h"
+
+VtConn*
+vtconn(int infd, int outfd)
+{
+ VtConn *z;
+
+ z = vtmallocz(sizeof(VtConn));
+ z->tagrend.l = &z->lk;
+ z->rpcfork.l = &z->lk;
+ z->infd = infd;
+ z->outfd = outfd;
+ z->part = packetalloc();
+ return z;
+}
+
+void
+vtfreeconn(VtConn *z)
+{
+ vthangup(z);
+ qlock(&z->lk);
+ for(;;){
+ if(z->readq)
+ _vtqhangup(z->readq);
+ else if(z->writeq)
+ _vtqhangup(z->writeq);
+ else
+ break;
+ rsleep(&z->rpcfork);
+ }
+ packetfree(z->part);
+ vtfree(z);
+}
(DIR) diff --git a/src/libventi/cvt.h b/src/libventi/cvt.h
t@@ -0,0 +1,15 @@
+/*
+ * integer conversion routines
+ */
+#define U8GET(p) ((p)[0])
+#define U16GET(p) (((p)[0]<<8)|(p)[1])
+#define U32GET(p) ((u32int)(((p)[0]<<24)|((p)[1]<<16)|((p)[2]<<8)|(p)[3]))
+#define U48GET(p) (((vlong)U16GET(p)<<32)|(vlong)U32GET((p)+2))
+#define U64GET(p) (((vlong)U32GET(p)<<32)|(vlong)U32GET((p)+4))
+
+#define U8PUT(p,v) (p)[0]=(v)
+#define U16PUT(p,v) (p)[0]=(v)>>8;(p)[1]=(v)
+#define U32PUT(p,v) (p)[0]=(v)>>24;(p)[1]=(v)>>16;(p)[2]=(v)>>8;(p)[3]=(v)
+#define U48PUT(p,v,t32) t32=(v)>>32;U16PUT(p,t32);t32=(v);U32PUT((p)+2,t32)
+#define U64PUT(p,v,t32) t32=(v)>>32;U32PUT(p,t32);t32=(v);U32PUT((p)+4,t32)
+
(DIR) diff --git a/src/libventi/debug.c b/src/libventi/debug.c
t@@ -0,0 +1,17 @@
+#include <u.h>
+#include <libc.h>
+#include <venti.h>
+
+void
+vtdebug(VtConn *z, char *fmt, ...)
+{
+ va_list arg;
+
+ if(z->debug == 0)
+ return;
+
+ va_start(arg, fmt);
+ vfprint(2, fmt, arg);
+ va_end(arg);
+}
+
(DIR) diff --git a/src/libventi/dial.c b/src/libventi/dial.c
t@@ -0,0 +1,21 @@
+#include <u.h>
+#include <libc.h>
+#include <venti.h>
+
+VtConn*
+vtdial(char *addr)
+{
+ char *na;
+ int fd;
+
+ if(addr == nil)
+ addr = getenv("venti");
+ if(addr == nil)
+ addr = "$venti";
+
+ na = netmkaddr(addr, "net", "venti");
+ if((fd = dial(na, nil, nil, nil)) < 0)
+ return nil;
+
+ return vtconn(fd, fd);
+}
(DIR) diff --git a/src/libventi/dtype.c b/src/libventi/dtype.c
t@@ -0,0 +1,78 @@
+#include <u.h>
+#include <libc.h>
+#include <venti.h>
+
+enum {
+ OVtErrType, /* illegal */
+
+ OVtRootType,
+ OVtDirType,
+ OVtPointerType0,
+ OVtPointerType1,
+ OVtPointerType2,
+ OVtPointerType3,
+ OVtPointerType4,
+ OVtPointerType5,
+ OVtPointerType6,
+ OVtPointerType7, /* not used */
+ OVtPointerType8, /* not used */
+ OVtPointerType9, /* not used */
+ OVtDataType,
+
+ OVtMaxType
+};
+
+
+uint todisk[] = {
+ OVtDataType,
+ OVtPointerType0,
+ OVtPointerType1,
+ OVtPointerType2,
+ OVtPointerType3,
+ OVtPointerType4,
+ OVtPointerType5,
+ OVtPointerType6,
+ OVtDirType,
+ OVtPointerType0,
+ OVtPointerType1,
+ OVtPointerType2,
+ OVtPointerType3,
+ OVtPointerType4,
+ OVtPointerType5,
+ OVtPointerType6,
+ OVtRootType,
+};
+
+uint fromdisk[] = {
+ ~0,
+ VtRootType,
+ VtDirType,
+ VtDirType+1,
+ VtDirType+2,
+ VtDirType+3,
+ VtDirType+4,
+ VtDirType+5,
+ VtDirType+6,
+ VtDirType+7,
+ ~0,
+ ~0,
+ ~0,
+ VtDataType,
+};
+
+uint
+vttodisktype(uint n)
+{
+ if(n >= nelem(todisk))
+ return ~0;
+ return todisk[n];
+}
+
+uint
+vtfromdisktype(uint n)
+{
+ if(n >= nelem(fromdisk))
+ return ~0;
+ return fromdisk[n];
+}
+
(DIR) diff --git a/src/libventi/entry.c b/src/libventi/entry.c
t@@ -0,0 +1,85 @@
+#include <u.h>
+#include <libc.h>
+#include <venti.h>
+#include "cvt.h"
+
+static int
+checksize(int n)
+{
+ if(n < 256 || n > VtMaxLumpSize) {
+ werrstr("bad block size");
+ return -1;
+ }
+ return 0;
+}
+
+void
+vtentrypack(VtEntry *e, uchar *p, int index)
+{
+ ulong t32;
+ int flags;
+ uchar *op;
+ int depth;
+
+ p += index * VtEntrySize;
+ op = p;
+
+ U32PUT(p, e->gen);
+ p += 4;
+ U16PUT(p, e->psize);
+ p += 2;
+ U16PUT(p, e->dsize);
+ p += 2;
+ depth = e->type&VtTypeDepthMask;
+ flags = (e->flags&~(VtEntryDir|VtEntryDepthShift));
+ flags |= depth << VtEntryDepthShift;
+ if(e->type - depth == VtEntryDir)
+ flags |= VtEntryDir;
+ U8PUT(p, flags);
+ p++;
+ memset(p, 0, 5);
+ p += 5;
+ U48PUT(p, e->size, t32);
+ p += 6;
+ memmove(p, e->score, VtScoreSize);
+ p += VtScoreSize;
+
+ assert(p-op == VtEntrySize);
+}
+
+int
+vtentryunpack(VtEntry *e, uchar *p, int index)
+{
+ uchar *op;
+
+ p += index * VtEntrySize;
+ op = p;
+
+ e->gen = U32GET(p);
+ p += 4;
+ e->psize = U16GET(p);
+ p += 2;
+ e->dsize = U16GET(p);
+ p += 2;
+ e->flags = U8GET(p);
+ e->type = (e->flags&VtEntryDir) ? VtDirType : VtDataType;
+ e->type += (e->flags & VtEntryDepthMask) >> VtEntryDepthShift;
+ e->flags &= ~(VtEntryDir|VtEntryDepthMask);
+ p++;
+ p += 5;
+ e->size = U48GET(p);
+ p += 6;
+ memmove(e->score, p, VtScoreSize);
+ p += VtScoreSize;
+
+ assert(p-op == VtEntrySize);
+
+ if(!(e->flags & VtEntryActive))
+ return 0;
+
+ if(checksize(e->psize) < 0 || checksize(e->dsize) < 0)
+ return -1;
+
+ return 0;
+}
+
(DIR) diff --git a/src/libventi/fcall.c b/src/libventi/fcall.c
t@@ -0,0 +1,230 @@
+#include <u.h>
+#include <libc.h>
+#include <venti.h>
+
+Packet*
+vtfcallpack(VtFcall *f)
+{
+ uchar buf[4];
+ Packet *p;
+
+ p = packetalloc();
+
+ buf[0] = f->type;
+ buf[1] = f->tag;
+ packetappend(p, buf, 2);
+
+ switch(f->type){
+ default:
+ werrstr("vtfcallpack: unknown packet type %d", f->type);
+ goto Err;
+
+ case VtRerror:
+ if(vtputstring(p, f->error) < 0)
+ goto Err;
+ break;
+
+ case VtTping:
+ break;
+
+ case VtRping:
+ break;
+
+ case VtThello:
+ if(vtputstring(p, f->version) < 0
+ || vtputstring(p, f->uid) < 0)
+ goto Err;
+ buf[0] = f->strength;
+ buf[1] = f->ncrypto;
+ packetappend(p, buf, 2);
+ packetappend(p, f->crypto, f->ncrypto);
+ buf[0] = f->ncodec;
+ packetappend(p, buf, 1);
+ packetappend(p, f->codec, f->ncodec);
+ break;
+
+ case VtRhello:
+ if(vtputstring(p, f->sid) < 0)
+ goto Err;
+ buf[0] = f->rcrypto;
+ buf[1] = f->rcodec;
+ packetappend(p, buf, 2);
+ break;
+
+ case VtTgoodbye:
+ break;
+
+ case VtTread:
+ packetappend(p, f->score, VtScoreSize);
+ buf[0] = vttodisktype(f->dtype);
+ if(~buf[0] == 0)
+ goto Err;
+ buf[1] = 0;
+ buf[2] = f->count >> 8;
+ buf[3] = f->count;
+ packetappend(p, buf, 4);
+ break;
+
+ case VtRread:
+ packetconcat(p, f->data);
+ break;
+
+ case VtTwrite:
+ buf[0] = vttodisktype(f->dtype);
+ if(~buf[0] == 0)
+ goto Err;
+ buf[1] = 0;
+ buf[2] = 0;
+ buf[3] = 0;
+ packetappend(p, buf, 4);
+ packetconcat(p, f->data);
+ break;
+
+ case VtRwrite:
+ packetappend(p, f->score, VtScoreSize);
+ break;
+
+ case VtTsync:
+ break;
+
+ case VtRsync:
+ break;
+ }
+
+ return p;
+
+Err:
+ packetfree(p);
+ return nil;
+}
+
+int
+vtfcallunpack(VtFcall *f, Packet *p)
+{
+ uchar buf[4];
+
+ memset(f, 0, sizeof *f);
+
+ if(packetconsume(p, buf, 2) < 0)
+ return -1;
+
+ f->type = buf[0];
+ f->tag = buf[1];
+
+ switch(f->type){
+ default:
+ werrstr("vtfcallunpack: unknown bad packet type %d", f->type);
+ vtfcallclear(f);
+ return -1;
+
+ case VtRerror:
+ if(vtgetstring(p, &f->error) < 0)
+ goto Err;
+ break;
+
+ case VtTping:
+ break;
+
+ case VtRping:
+ break;
+
+ case VtThello:
+ if(vtgetstring(p, &f->version) < 0
+ || vtgetstring(p, &f->uid) < 0
+ || packetconsume(p, buf, 2) < 0)
+ goto Err;
+ f->strength = buf[0];
+ f->ncrypto = buf[1];
+ if(f->ncrypto){
+ f->crypto = vtmalloc(f->ncrypto);
+ if(packetconsume(p, buf, f->ncrypto) < 0)
+ goto Err;
+ }
+ if(packetconsume(p, buf, 1) < 0)
+ goto Err;
+ f->ncodec = buf[0];
+ if(f->ncodec){
+ f->codec = vtmalloc(f->ncodec);
+ if(packetconsume(p, buf, f->ncodec) < 0)
+ goto Err;
+ }
+ break;
+
+ case VtRhello:
+ if(vtgetstring(p, &f->sid) < 0
+ || packetconsume(p, buf, 2) < 0)
+ goto Err;
+ f->rcrypto = buf[0];
+ f->rcodec = buf[1];
+ break;
+
+ case VtTgoodbye:
+ break;
+
+ case VtTread:
+ if(packetconsume(p, f->score, VtScoreSize) < 0
+ || packetconsume(p, buf, 4) < 0)
+ goto Err;
+ f->dtype = vtfromdisktype(buf[0]);
+ if(~f->dtype == 0)
+ goto Err;
+ f->count = (buf[2] << 8) | buf[3];
+ break;
+
+ case VtRread:
+ f->data = packetalloc();
+ packetconcat(f->data, p);
+ break;
+
+ case VtTwrite:
+ if(packetconsume(p, buf, 4) < 0)
+ goto Err;
+ f->dtype = vtfromdisktype(buf[0]);
+ if(~f->dtype == 0)
+ goto Err;
+ f->data = packetalloc();
+ packetconcat(f->data, p);
+ break;
+
+ case VtRwrite:
+ if(packetconsume(p, f->score, VtScoreSize) < 0)
+ goto Err;
+ break;
+
+ case VtTsync:
+ break;
+
+ case VtRsync:
+ break;
+ }
+
+ if(packetsize(p) != 0)
+ goto Err;
+
+ return 0;
+
+Err:
+ werrstr("bad packet");
+ return -1;
+}
+
+void
+vtfcallclear(VtFcall *f)
+{
+ vtfree(f->error);
+ f->error = nil;
+ vtfree(f->uid);
+ f->uid = nil;
+ vtfree(f->sid);
+ f->sid = nil;
+ vtfree(f->version);
+ f->version = nil;
+ vtfree(f->crypto);
+ f->crypto = nil;
+ vtfree(f->codec);
+ f->codec = nil;
+ vtfree(f->auth);
+ f->auth = nil;
+ packetfree(f->data);
+ f->auth = nil;
+}
(DIR) diff --git a/src/libventi/fcallfmt.c b/src/libventi/fcallfmt.c
t@@ -0,0 +1,55 @@
+#include <u.h>
+#include <libc.h>
+#include <venti.h>
+
+int
+vtfcallfmt(Fmt *f)
+{
+ VtFcall *t;
+
+ t = va_arg(f->args, VtFcall*);
+ if(t == nil){
+ fmtprint(f, "<nil fcall>");
+ return 0;
+ }
+ switch(t->type){
+ default:
+ return fmtprint(f, "%c%d tag %ud", "TR"[t->type&1], t->type>>1, t->tag);
+ case VtRerror:
+ return fmtprint(f, "Rerror tag %ud error %s", t->tag, t->error);
+ case VtTping:
+ return fmtprint(f, "Tping tag %ud", t->tag);
+ case VtRping:
+ return fmtprint(f, "Rping tag %ud", t->tag);
+ case VtThello:
+ return fmtprint(f, "Thello tag %ud vers %s uid %s strength %d crypto %d:%.*H codec %d:%.*H", t->tag,
+ t->version, t->uid, t->strength, t->ncrypto, t->ncrypto, t->crypto,
+ t->ncodec, t->ncodec, t->codec);
+ case VtRhello:
+ return fmtprint(f, "Rhello tag %ud sid %s rcrypto %d rcodec %d", t->tag, t->sid, t->rcrypto, t->rcodec);
+ case VtTgoodbye:
+ return fmtprint(f, "Tgoodbye tag %ud", t->tag);
+ case VtRgoodbye:
+ return fmtprint(f, "Rgoodbye tag %ud", t->tag);
+ case VtTauth0:
+ return fmtprint(f, "Tauth0 tag %ud auth %.*H", t->tag, t->nauth, t->auth);
+ case VtRauth0:
+ return fmtprint(f, "Rauth0 tag %ud auth %.*H", t->tag, t->nauth, t->auth);
+ case VtTauth1:
+ return fmtprint(f, "Tauth1 tag %ud auth %.*H", t->tag, t->nauth, t->auth);
+ case VtRauth1:
+ return fmtprint(f, "Rauth1 tag %ud auth %.*H", t->tag, t->nauth, t->auth);
+ case VtTread:
+ return fmtprint(f, "Tread tag %ud score %V dtype %d count %d", t->tag, t->score, t->dtype, t->count);
+ case VtRread:
+ return fmtprint(f, "Rread tag %ud count %d", t->tag, packetsize(t->data));
+ case VtTwrite:
+ return fmtprint(f, "Twrite tag %ud dtype %d count %d", t->tag, t->dtype, packetsize(t->data));
+ case VtRwrite:
+ return fmtprint(f, "Rwrite tag %ud score %V", t->tag, t->score);
+ case VtTsync:
+ return fmtprint(f, "Tsync tag %ud", t->tag);
+ case VtRsync:
+ return fmtprint(f, "Rsync tag %ud", t->tag);
+ }
+}
(DIR) diff --git a/src/libventi/file.c b/src/libventi/file.c
t@@ -0,0 +1,1264 @@
+/*
+ * Manage tree of VtFiles stored in the block cache.
+ *
+ * The single point of truth for the info about the VtFiles themselves
+ * is the block data. Because of this, there is no explicit locking of
+ * VtFile structures, and indeed there may be more than one VtFile
+ * structure for a given Venti file. They synchronize through the
+ * block cache.
+ *
+ * This is a bit simpler than fossil because there are no epochs
+ * or tags or anything else. Just mutable local blocks and immutable
+ * Venti blocks.
+ */
+
+#include <u.h>
+#include <libc.h>
+#include <venti.h>
+
+enum
+{
+ MaxBlock = (1UL<<31),
+};
+
+struct VtFile
+{
+ QLock lk;
+ int ref;
+ int local;
+ VtBlock *b; /* block containing this file */
+ uchar score[VtScoreSize]; /* score of block containing this file */
+
+/* immutable */
+ VtCache *c;
+ int mode;
+ u32int gen;
+ int dsize;
+ int dir;
+ VtFile *parent;
+ int epb; /* entries per block in parent */
+ u32int offset; /* entry offset in parent */
+};
+
+static char EBadEntry[] = "bad VtEntry";
+static char ENotDir[] = "walk in non-directory";
+static char ETooBig[] = "file too big";
+static char EBadAddr[] = "bad address";
+static char ELabelMismatch[] = "label mismatch";
+
+static int sizetodepth(uvlong s, int psize, int dsize);
+static VtBlock *fileload(VtFile *r, VtEntry *e);
+static int shrinkdepth(VtFile*, VtBlock*, VtEntry*, int);
+static int shrinksize(VtFile*, VtEntry*, uvlong);
+static int growdepth(VtFile*, VtBlock*, VtEntry*, int);
+
+#define ISLOCKED(r) ((r)->b != nil)
+#define DEPTH(t) ((t)&VtTypeDepthMask)
+
+static VtFile *
+vtfilealloc(VtCache *c, VtBlock *b, VtFile *p, u32int offset, int mode)
+{
+ int epb;
+ u32int size;
+ VtEntry e;
+ VtFile *r;
+
+ assert(p==nil || ISLOCKED(p));
+
+ if(p == nil){
+ assert(offset == 0);
+ epb = 1;
+ }else
+ epb = p->dsize / VtEntrySize;
+
+ if(b->type != VtDirType)
+ goto Bad;
+
+ /*
+ * a non-active entry is the only thing that
+ * can legitimately happen here. all the others
+ * get prints.
+ */
+ if(vtentryunpack(&e, b->data, offset % epb) < 0){
+ fprint(2, "vtentryunpack failed\n");
+ goto Bad;
+ }
+ if(!(e.flags & VtEntryActive)){
+ if(0)fprint(2, "not active\n");
+ goto Bad;
+ }
+ if(e.psize < 256 || e.dsize < 256){
+ fprint(2, "psize %ud dsize %ud\n", e.psize, e.dsize);
+ goto Bad;
+ }
+
+ if(DEPTH(e.type) < sizetodepth(e.size, e.psize, e.dsize)){
+ fprint(2, "depth %ud size %llud psize %ud dsize %ud\n",
+ DEPTH(e.type), e.size, e.psize, e.dsize);
+ goto Bad;
+ }
+
+ size = vtcacheblocksize(c);
+ if(e.dsize > size || e.psize > size){
+ fprint(2, "psize %ud dsize %ud blocksize %ud\n", e.psize, e.dsize, size);
+ goto Bad;
+ }
+
+ r = vtmallocz(sizeof(VtFile));
+ r->c = c;
+ r->mode = mode;
+ r->dsize = e.dsize;
+ r->gen = e.gen;
+ r->dir = (e.flags & VtEntryDir) != 0;
+ r->ref = 1;
+ r->parent = p;
+ if(p){
+ qlock(&p->lk);
+ assert(mode == VtOREAD || p->mode == VtORDWR);
+ p->ref++;
+ qunlock(&p->lk);
+ }
+ memmove(r->score, b->score, VtScoreSize);
+ r->offset = offset;
+ r->epb = epb;
+
+ return r;
+Bad:
+ werrstr(EBadEntry);
+ return nil;
+
+}
+
+VtFile *
+vtfileroot(VtCache *c, u32int addr, int mode)
+{
+ VtFile *r;
+ VtBlock *b;
+
+ b = vtcachelocal(c, addr, VtDirType);
+ if(b == nil)
+ return nil;
+
+ r = vtfilealloc(c, b, nil, 0, mode);
+ vtblockput(b);
+ return r;
+}
+
+VtFile*
+vtfileopenroot(VtCache *c, VtEntry *e)
+{
+ VtBlock *b;
+ VtFile *f;
+
+ b = vtcacheallocblock(c, VtDirType);
+ if(b == nil)
+ return nil;
+
+ vtentrypack(e, b->data, 0);
+ f = vtfilealloc(c, b, nil, 0, VtORDWR);
+ vtblockput(b);
+ return f;
+}
+
+VtFile *
+vtfilecreateroot(VtCache *c, int psize, int dsize, int type)
+{
+ VtEntry e;
+
+ memset(&e, 0, sizeof e);
+ e.flags = VtEntryActive;
+ e.psize = psize;
+ e.dsize = dsize;
+ if(type == VtDirType)
+ e.flags |= VtEntryDir;
+ memmove(e.score, vtzeroscore, VtScoreSize);
+
+ return vtfileopenroot(c, &e);
+}
+
+VtFile *
+vtfileopen(VtFile *r, u32int offset, int mode)
+{
+ ulong bn;
+ VtBlock *b;
+
+ assert(ISLOCKED(r));
+ if(!r->dir){
+ werrstr(ENotDir);
+ return nil;
+ }
+
+ bn = offset/(r->dsize/VtEntrySize);
+
+ b = vtfileblock(r, bn, mode);
+ if(b == nil)
+ return nil;
+ r = vtfilealloc(r->c, b, r, offset, mode);
+ vtblockput(b);
+ return r;
+}
+
+VtFile *
+vtfilecreate(VtFile *r, int psize, int dsize, int dir)
+{
+ int i;
+ VtBlock *b;
+ u32int bn, size;
+ VtEntry e;
+ int epb;
+ VtFile *rr;
+ u32int offset;
+
+ assert(ISLOCKED(r));
+
+ if(!r->dir){
+ werrstr(ENotDir);
+ return nil;
+ }
+
+ epb = r->dsize/VtEntrySize;
+
+ size = vtfilegetdirsize(r);
+ /*
+ * look at a random block to see if we can find an empty entry
+ */
+ offset = lnrand(size+1);
+ offset -= offset % epb;
+
+ /* try the given block and then try the last block */
+ for(;;){
+ bn = offset/epb;
+ b = vtfileblock(r, bn, VtORDWR);
+ if(b == nil)
+ return nil;
+ for(i=offset%r->epb; i<epb; i++){
+ if(vtentryunpack(&e, b->data, i) < 0)
+ continue;
+ if((e.flags&VtEntryActive) == 0 && e.gen != ~0)
+ goto Found;
+ }
+ vtblockput(b);
+ if(offset == size){
+ fprint(2, "vtfilecreate: cannot happen\n");
+ werrstr("vtfilecreate: cannot happen");
+ return nil;
+ }
+ offset = size;
+ }
+
+Found:
+ /* found an entry - gen already set */
+ e.psize = psize;
+ e.dsize = dsize;
+ e.flags = VtEntryActive;
+ e.type = dir ? VtDirType : VtDataType;
+ e.size = 0;
+ memmove(e.score, vtzeroscore, VtScoreSize);
+ vtentrypack(&e, b->data, i);
+
+ offset = bn*epb + i;
+ if(offset+1 > size){
+ if(vtfilesetdirsize(r, offset+1) < 0){
+ vtblockput(b);
+ return nil;
+ }
+ }
+
+ rr = vtfilealloc(r->c, b, r, offset, VtORDWR);
+ vtblockput(b);
+ return rr;
+}
+
+static int
+vtfilekill(VtFile *r, int doremove)
+{
+ VtEntry e;
+ VtBlock *b;
+
+ assert(ISLOCKED(r));
+ b = fileload(r, &e);
+ if(b == nil)
+ return -1;
+
+ if(doremove==0 && e.size == 0){
+ /* already truncated */
+ vtblockput(b);
+ return 0;
+ }
+
+ if(doremove){
+ if(e.gen != ~0)
+ e.gen++;
+ e.dsize = 0;
+ e.psize = 0;
+ e.flags = 0;
+ }else
+ e.flags &= ~VtEntryLocal;
+ e.type = 0;
+ e.size = 0;
+ memmove(e.score, vtzeroscore, VtScoreSize);
+ vtentrypack(&e, b->data, r->offset % r->epb);
+ vtblockput(b);
+
+ if(doremove){
+ vtfileunlock(r);
+ vtfileclose(r);
+ }
+
+ return 0;
+}
+
+int
+vtfileremove(VtFile *r)
+{
+ return vtfilekill(r, 1);
+}
+
+int
+vtfiletruncate(VtFile *r)
+{
+ return vtfilekill(r, 0);
+}
+
+uvlong
+vtfilegetsize(VtFile *r)
+{
+ VtEntry e;
+ VtBlock *b;
+
+ assert(ISLOCKED(r));
+ b = fileload(r, &e);
+ if(b == nil)
+ return ~(uvlong)0;
+ vtblockput(b);
+
+ return e.size;
+}
+
+static int
+shrinksize(VtFile *r, VtEntry *e, uvlong size)
+{
+ int i, depth, type, isdir, ppb;
+ uvlong ptrsz;
+ uchar score[VtScoreSize];
+ VtBlock *b;
+
+ b = vtcacheglobal(r->c, e->score, e->type);
+ if(b == nil)
+ return -1;
+
+ ptrsz = e->dsize;
+ ppb = e->psize/VtScoreSize;
+ type = e->type;
+ depth = DEPTH(type);
+ for(i=0; i+1<depth; i++)
+ ptrsz *= ppb;
+
+ isdir = r->dir;
+ while(depth > 0){
+ if(b->addr == NilBlock){
+ /* not worth copying the block just so we can zero some of it */
+ vtblockput(b);
+ return -1;
+ }
+
+ /*
+ * invariant: each pointer in the tree rooted at b accounts for ptrsz bytes
+ */
+
+ /* zero the pointers to unnecessary blocks */
+ i = (size+ptrsz-1)/ptrsz;
+ for(; i<ppb; i++)
+ memmove(b->data+i*VtScoreSize, vtzeroscore, VtScoreSize);
+
+ /* recurse (go around again) on the partially necessary block */
+ i = size/ptrsz;
+ size = size%ptrsz;
+ if(size == 0){
+ vtblockput(b);
+ return 0;
+ }
+ ptrsz /= ppb;
+ type--;
+ memmove(score, b->data+i*VtScoreSize, VtScoreSize);
+ vtblockput(b);
+ b = vtcacheglobal(r->c, score, type);
+ if(b == nil)
+ return -1;
+ }
+
+ if(b->addr == NilBlock){
+ vtblockput(b);
+ return -1;
+ }
+
+ /*
+ * No one ever truncates BtDir blocks.
+ */
+ if(depth==0 && !isdir && e->dsize > size)
+ memset(b->data+size, 0, e->dsize-size);
+ vtblockput(b);
+ return 0;
+}
+
+int
+vtfilesetsize(VtFile *r, uvlong size)
+{
+ int depth, edepth;
+ VtEntry e;
+ VtBlock *b;
+
+ assert(ISLOCKED(r));
+ if(size == 0)
+ return vtfiletruncate(r);
+
+ if(size > VtMaxFileSize || size > ((uvlong)MaxBlock)*r->dsize){
+ werrstr(ETooBig);
+ return -1;
+ }
+
+ b = fileload(r, &e);
+ if(b == nil)
+ return -1;
+
+ /* quick out */
+ if(e.size == size){
+ vtblockput(b);
+ return 0;
+ }
+
+ depth = sizetodepth(size, e.psize, e.dsize);
+ edepth = DEPTH(e.type);
+ if(depth < edepth){
+ if(shrinkdepth(r, b, &e, depth) < 0){
+ vtblockput(b);
+ return -1;
+ }
+ }else if(depth > edepth){
+ if(growdepth(r, b, &e, depth) < 0){
+ vtblockput(b);
+ return -1;
+ }
+ }
+
+ if(size < e.size)
+ shrinksize(r, &e, size);
+
+ e.size = size;
+ vtentrypack(&e, b->data, r->offset % r->epb);
+ vtblockput(b);
+
+ return 0;
+}
+
+int
+vtfilesetdirsize(VtFile *r, u32int ds)
+{
+ uvlong size;
+ int epb;
+
+ assert(ISLOCKED(r));
+ epb = r->dsize/VtEntrySize;
+
+ size = (uvlong)r->dsize*(ds/epb);
+ size += VtEntrySize*(ds%epb);
+ return vtfilesetsize(r, size);
+}
+
+u32int
+vtfilegetdirsize(VtFile *r)
+{
+ ulong ds;
+ uvlong size;
+ int epb;
+
+ assert(ISLOCKED(r));
+ epb = r->dsize/VtEntrySize;
+
+ size = vtfilegetsize(r);
+ ds = epb*(size/r->dsize);
+ ds += (size%r->dsize)/VtEntrySize;
+ return ds;
+}
+
+int
+vtfilegetentry(VtFile *r, VtEntry *e)
+{
+ VtBlock *b;
+
+ assert(ISLOCKED(r));
+ b = fileload(r, e);
+ if(b == nil)
+ return -1;
+ vtblockput(b);
+
+ return 0;
+}
+
+int
+vtfilesetentry(VtFile *r, VtEntry *e)
+{
+ VtBlock *b;
+ VtEntry ee;
+
+ assert(ISLOCKED(r));
+ b = fileload(r, &ee);
+ if(b == nil)
+ return -1;
+ vtentrypack(e, b->data, r->offset % r->epb);
+ vtblockput(b);
+ return 0;
+}
+
+static VtBlock *
+blockwalk(VtBlock *p, int index, VtCache *c, int mode, VtEntry *e)
+{
+ VtBlock *b;
+ int type;
+ uchar *score;
+ VtEntry oe;
+
+ switch(p->type){
+ case VtDataType:
+ assert(0);
+ case VtDirType:
+ type = e->type;
+ score = e->score;
+ break;
+ default:
+ type = p->type - 1;
+ score = p->data+index*VtScoreSize;
+ break;
+ }
+//print("walk from %V/%d ty %d to %V ty %d\n", p->score, index, p->type, score, type);
+
+ if(mode == VtOWRITE && vtglobaltolocal(score) == NilBlock){
+ b = vtcacheallocblock(c, type);
+ if(b)
+ goto HaveCopy;
+ }else
+ b = vtcacheglobal(c, score, type);
+
+ if(b == nil || mode == VtOREAD)
+ return b;
+
+ if(vtglobaltolocal(b->score) != NilBlock)
+ return b;
+
+ oe = *e;
+
+ /*
+ * Copy on write.
+ */
+ e->flags |= VtEntryLocal;
+
+ b = vtblockcopy(b/*, e->tag, fs->ehi, fs->elo*/);
+ if(b == nil)
+ return nil;
+
+HaveCopy:
+ if(p->type == VtDirType){
+ memmove(e->score, b->score, VtScoreSize);
+ vtentrypack(e, p->data, index);
+ }else{
+ memmove(p->data+index*VtScoreSize, b->score, VtScoreSize);
+ }
+ return b;
+}
+
+/*
+ * Change the depth of the VtFile r.
+ * The entry e for r is contained in block p.
+ */
+static int
+growdepth(VtFile *r, VtBlock *p, VtEntry *e, int depth)
+{
+ VtBlock *b, *bb;
+ VtEntry oe;
+
+ assert(ISLOCKED(r));
+ assert(depth <= VtPointerDepth);
+
+ b = vtcacheglobal(r->c, e->score, e->type);
+ if(b == nil)
+ return -1;
+
+ oe = *e;
+
+ /*
+ * Keep adding layers until we get to the right depth
+ * or an error occurs.
+ */
+ while(DEPTH(e->type) < depth){
+ bb = vtcacheallocblock(r->c, e->type+1);
+ if(bb == nil)
+ break;
+ memmove(bb->data, b->score, VtScoreSize);
+ memmove(e->score, bb->score, VtScoreSize);
+ e->type++;
+ e->flags |= VtEntryLocal;
+ vtblockput(b);
+ b = bb;
+ }
+
+ vtentrypack(e, p->data, r->offset % r->epb);
+ vtblockput(b);
+
+ if(DEPTH(e->type) == depth)
+ return 0;
+ return -1;
+}
+
+static int
+shrinkdepth(VtFile *r, VtBlock *p, VtEntry *e, int depth)
+{
+ VtBlock *b, *nb, *ob, *rb;
+ VtEntry oe;
+
+ assert(ISLOCKED(r));
+ assert(depth <= VtPointerDepth);
+
+ rb = vtcacheglobal(r->c, e->score, e->type);
+ if(rb == nil)
+ return 0;
+
+ /*
+ * Walk down to the new root block.
+ * We may stop early, but something is better than nothing.
+ */
+ oe = *e;
+
+ ob = nil;
+ b = rb;
+ for(; DEPTH(e->type) > depth; e->type--){
+ nb = vtcacheglobal(r->c, b->data, e->type-1);
+ if(nb == nil)
+ break;
+ if(ob!=nil && ob!=rb)
+ vtblockput(ob);
+ ob = b;
+ b = nb;
+ }
+
+ if(b == rb){
+ vtblockput(rb);
+ return 0;
+ }
+
+ /*
+ * Right now, e points at the root block rb, b is the new root block,
+ * and ob points at b. To update:
+ *
+ * (i) change e to point at b
+ * (ii) zero the pointer ob -> b
+ * (iii) free the root block
+ *
+ * p (the block containing e) must be written before
+ * anything else.
+ */
+
+ /* (i) */
+ memmove(e->score, b->score, VtScoreSize);
+ vtentrypack(e, p->data, r->offset % r->epb);
+
+ /* (ii) */
+ memmove(ob->data, vtzeroscore, VtScoreSize);
+
+ /* (iii) */
+ vtblockput(rb);
+ if(ob!=nil && ob!=rb)
+ vtblockput(ob);
+ vtblockput(b);
+
+ if(DEPTH(e->type) == depth)
+ return 0;
+ return -1;
+}
+
+static int
+mkindices(VtEntry *e, u32int bn, int *index)
+{
+ int i, np;
+
+ memset(index, 0, VtPointerDepth*sizeof(int));
+
+ np = e->psize/VtScoreSize;
+ for(i=0; bn > 0; i++){
+ if(i >= VtPointerDepth){
+ werrstr(EBadAddr);
+ return -1;
+ }
+ index[i] = bn % np;
+ bn /= np;
+ }
+ return i;
+}
+
+VtBlock *
+vtfileblock(VtFile *r, u32int bn, int mode)
+{
+ VtBlock *b, *bb;
+ int index[VtPointerDepth+1];
+ VtEntry e;
+ int i;
+ int m;
+
+ assert(ISLOCKED(r));
+ assert(bn != NilBlock);
+
+ b = fileload(r, &e);
+ if(b == nil)
+ return nil;
+
+ i = mkindices(&e, bn, index);
+ if(i < 0)
+ return nil;
+ if(i > DEPTH(e.type)){
+ if(mode == VtOREAD){
+ werrstr(EBadAddr);
+ goto Err;
+ }
+ index[i] = 0;
+ if(growdepth(r, b, &e, i) < 0)
+ goto Err;
+ }
+
+assert(b->type == VtDirType);
+
+ index[DEPTH(e.type)] = r->offset % r->epb;
+
+ /* mode for intermediate block */
+ m = mode;
+ if(m == VtOWRITE)
+ m = VtORDWR;
+
+ for(i=DEPTH(e.type); i>=0; i--){
+ bb = blockwalk(b, index[i], r->c, i==0 ? mode : m, &e);
+ if(bb == nil)
+ goto Err;
+ vtblockput(b);
+ b = bb;
+ }
+ return b;
+Err:
+ vtblockput(b);
+ return nil;
+}
+
+int
+vtfileblockhash(VtFile *r, u32int bn, uchar score[VtScoreSize])
+{
+ VtBlock *b, *bb;
+ int index[VtPointerDepth+1];
+ VtEntry e;
+ int i;
+
+ assert(ISLOCKED(r));
+ assert(bn != NilBlock);
+
+ b = fileload(r, &e);
+ if(b == nil)
+ return -1;
+
+ i = mkindices(&e, bn, index);
+ if(i < 0){
+ vtblockput(b);
+ return -1;
+ }
+ if(i > DEPTH(e.type)){
+ memmove(score, vtzeroscore, VtScoreSize);
+ vtblockput(b);
+ return 0;
+ }
+
+ index[DEPTH(e.type)] = r->offset % r->epb;
+
+ for(i=DEPTH(e.type); i>=1; i--){
+ bb = blockwalk(b, index[i], r->c, VtOREAD, &e);
+ if(bb == nil)
+ goto Err;
+ vtblockput(b);
+ b = bb;
+ if(memcmp(b->score, vtzeroscore, VtScoreSize) == 0)
+ break;
+ }
+
+ memmove(score, b->data+index[0]*VtScoreSize, VtScoreSize);
+ vtblockput(b);
+ return 0;
+
+Err:
+fprint(2, "vtfileblockhash: %r\n");
+ vtblockput(b);
+ return -1;
+}
+
+void
+vtfileincref(VtFile *r)
+{
+ qlock(&r->lk);
+ r->ref++;
+ qunlock(&r->lk);
+}
+
+void
+vtfileclose(VtFile *r)
+{
+ if(r == nil)
+ return;
+ qlock(&r->lk);
+ r->ref--;
+ if(r->ref){
+ qunlock(&r->lk);
+ return;
+ }
+ assert(r->ref == 0);
+ qunlock(&r->lk);
+ if(r->parent)
+ vtfileclose(r->parent);
+ memset(r, ~0, sizeof(*r));
+ vtfree(r);
+}
+
+/*
+ * Retrieve the block containing the entry for r.
+ * If a snapshot has happened, we might need
+ * to get a new copy of the block. We avoid this
+ * in the common case by caching the score for
+ * the block and the last epoch in which it was valid.
+ *
+ * We use r->mode to tell the difference between active
+ * file system VtFiles (VtORDWR) and VtFiles for the
+ * snapshot file system (VtOREAD).
+ */
+static VtBlock*
+fileloadblock(VtFile *r, int mode)
+{
+ char e[ERRMAX];
+ u32int addr;
+ VtBlock *b;
+
+ switch(r->mode){
+ default:
+ assert(0);
+ case VtORDWR:
+ assert(r->mode == VtORDWR);
+ if(r->local == 1){
+ b = vtcacheglobal(r->c, r->score, VtDirType);
+ if(b == nil)
+ return nil;
+ return b;
+ }
+ assert(r->parent != nil);
+ if(vtfilelock(r->parent, VtORDWR) < 0)
+ return nil;
+ b = vtfileblock(r->parent, r->offset/r->epb, VtORDWR);
+ vtfileunlock(r->parent);
+ if(b == nil)
+ return nil;
+ memmove(r->score, b->score, VtScoreSize);
+ r->local = 1;
+ return b;
+
+ case VtOREAD:
+ if(mode == VtORDWR){
+ werrstr("read/write lock of read-only file");
+ return nil;
+ }
+ addr = vtglobaltolocal(r->score);
+ if(addr == NilBlock)
+ return vtcacheglobal(r->c, r->score, VtDirType);
+
+ b = vtcachelocal(r->c, addr, VtDirType);
+ if(b)
+ return b;
+
+ /*
+ * If it failed because the epochs don't match, the block has been
+ * archived and reclaimed. Rewalk from the parent and get the
+ * new pointer. This can't happen in the VtORDWR case
+ * above because blocks in the current epoch don't get
+ * reclaimed. The fact that we're VtOREAD means we're
+ * a snapshot. (Or else the file system is read-only, but then
+ * the archiver isn't going around deleting blocks.)
+ */
+ rerrstr(e, sizeof e);
+ if(strcmp(e, ELabelMismatch) == 0){
+ if(vtfilelock(r->parent, VtOREAD) < 0)
+ return nil;
+ b = vtfileblock(r->parent, r->offset/r->epb, VtOREAD);
+ vtfileunlock(r->parent);
+ if(b){
+ fprint(2, "vtfilealloc: lost %V found %V\n",
+ r->score, b->score);
+ memmove(r->score, b->score, VtScoreSize);
+ return b;
+ }
+ }
+ return nil;
+ }
+}
+
+int
+vtfilelock(VtFile *r, int mode)
+{
+ VtBlock *b;
+
+ if(mode == -1)
+ mode = r->mode;
+
+ b = fileloadblock(r, mode);
+ if(b == nil)
+ return -1;
+ /*
+ * The fact that we are holding b serves as the
+ * lock entitling us to write to r->b.
+ */
+ assert(r->b == nil);
+ r->b = b;
+ return 0;
+}
+
+/*
+ * Lock two (usually sibling) VtFiles. This needs special care
+ * because the Entries for both vtFiles might be in the same block.
+ * We also try to lock blocks in left-to-right order within the tree.
+ */
+int
+vtfilelock2(VtFile *r, VtFile *rr, int mode)
+{
+ VtBlock *b, *bb;
+
+ if(rr == nil)
+ return vtfilelock(r, mode);
+
+ if(mode == -1)
+ mode = r->mode;
+
+ if(r->parent==rr->parent && r->offset/r->epb == rr->offset/rr->epb){
+ b = fileloadblock(r, mode);
+ if(b == nil)
+ return -1;
+ vtblockduplock(b);
+ bb = b;
+ }else if(r->parent==rr->parent || r->offset > rr->offset){
+ bb = fileloadblock(rr, mode);
+ b = fileloadblock(r, mode);
+ }else{
+ b = fileloadblock(r, mode);
+ bb = fileloadblock(rr, mode);
+ }
+ if(b == nil || bb == nil){
+ if(b)
+ vtblockput(b);
+ if(bb)
+ vtblockput(bb);
+ return -1;
+ }
+
+ /*
+ * The fact that we are holding b and bb serves
+ * as the lock entitling us to write to r->b and rr->b.
+ */
+ r->b = b;
+ rr->b = bb;
+ return 0;
+}
+
+void
+vtfileunlock(VtFile *r)
+{
+ VtBlock *b;
+
+ if(r->b == nil){
+ fprint(2, "vtfileunlock: already unlocked\n");
+ abort();
+ }
+ b = r->b;
+ r->b = nil;
+ vtblockput(b);
+}
+
+static VtBlock*
+fileload(VtFile *r, VtEntry *e)
+{
+ VtBlock *b;
+
+ assert(ISLOCKED(r));
+ b = r->b;
+ if(vtentryunpack(e, b->data, r->offset % r->epb) < 0)
+ return nil;
+ vtblockduplock(b);
+ return b;
+}
+
+static int
+sizetodepth(uvlong s, int psize, int dsize)
+{
+ int np;
+ int d;
+
+ /* determine pointer depth */
+ np = psize/VtScoreSize;
+ s = (s + dsize - 1)/dsize;
+ for(d = 0; s > 1; d++)
+ s = (s + np - 1)/np;
+ return d;
+}
+
+long
+vtfileread(VtFile *f, void *data, long count, vlong offset)
+{
+ int frag;
+ VtBlock *b;
+ VtEntry e;
+
+ assert(ISLOCKED(f));
+
+ vtfilegetentry(f, &e);
+ if(count == 0)
+ return 0;
+ if(count < 0 || offset < 0){
+ werrstr("vtfileread: bad offset or count");
+ return -1;
+ }
+ if(offset >= e.size)
+ return 0;
+
+ if(offset+count > e.size)
+ count = e.size - offset;
+
+ frag = offset % e.dsize;
+ if(frag+count > e.dsize)
+ count = e.dsize - frag;
+
+ b = vtfileblock(f, offset/e.dsize, VtOREAD);
+ if(b == nil)
+ return -1;
+
+ memmove(data, b->data+frag, count);
+ vtblockput(b);
+ return count;
+}
+
+static long
+filewrite1(VtFile *f, void *data, long count, vlong offset)
+{
+ int frag, m;
+ VtBlock *b;
+ VtEntry e;
+
+ vtfilegetentry(f, &e);
+ if(count < 0 || offset < 0){
+ werrstr("vtfilewrite: bad offset or count");
+ return -1;
+ }
+
+ frag = offset % e.dsize;
+ if(frag+count > e.dsize)
+ count = e.dsize - frag;
+
+ m = VtORDWR;
+ if(frag == 0 && count == e.dsize)
+ m = VtOWRITE;
+
+ b = vtfileblock(f, offset/e.dsize, m);
+ if(b == nil)
+ return -1;
+
+ memmove(b->data+frag, data, count);
+
+ if(offset+count > e.size){
+ vtfilegetentry(f, &e);
+ e.size = offset+count;
+ vtfilesetentry(f, &e);
+ }
+
+ vtblockput(b);
+ return count;
+}
+
+long
+vtfilewrite(VtFile *f, void *data, long count, vlong offset)
+{
+ long tot, m;
+
+ assert(ISLOCKED(f));
+
+ tot = 0;
+ m = 0;
+ while(tot < count){
+ m = filewrite1(f, (char*)data+tot, count-tot, offset+tot);
+ if(m <= 0)
+ break;
+ tot += m;
+ }
+ if(tot==0)
+ return m;
+ return tot;
+}
+
+static int
+flushblock(VtCache *c, VtBlock *bb, uchar score[VtScoreSize], int ppb, int epb,
+ int type)
+{
+ u32int addr;
+ VtBlock *b;
+ VtEntry e;
+ int i;
+
+ addr = vtglobaltolocal(score);
+ if(addr == NilBlock)
+ return 0;
+
+ if(bb){
+ b = bb;
+ if(memcmp(b->score, score, VtScoreSize) != 0)
+ abort();
+ }else
+ if((b = vtcachelocal(c, addr, type)) == nil)
+ return -1;
+
+ switch(type){
+ case VtDataType:
+ break;
+
+ case VtDirType:
+ for(i=0; i<epb; i++){
+ if(vtentryunpack(&e, b->data, i) < 0)
+ goto Err;
+ if(flushblock(c, nil, e.score, e.psize/VtScoreSize, e.dsize/VtEntrySize,
+ e.type) < 0)
+ goto Err;
+ }
+ break;
+
+ default: /* VtPointerTypeX */
+ for(i=0; i<ppb; i++){
+ if(flushblock(c, nil, b->data+VtScoreSize*i, ppb, epb, type-1) < 0)
+ goto Err;
+ }
+ break;
+ }
+
+ if(vtblockwrite(b) < 0)
+ goto Err;
+ memmove(score, b->score, VtScoreSize);
+ if(b != bb)
+ vtblockput(b);
+ return 0;
+
+Err:
+ if(b != bb)
+ vtblockput(b);
+ return -1;
+}
+
+int
+vtfileflush(VtFile *f)
+{
+ int ret;
+ VtBlock *b;
+ VtEntry e;
+
+ assert(ISLOCKED(f));
+ b = fileload(f, &e);
+ if(!(e.flags&VtEntryLocal)){
+ vtblockput(b);
+ return 0;
+ }
+
+ ret = flushblock(f->c, nil, e.score, e.psize/VtScoreSize, e.dsize/VtEntrySize,
+ e.type);
+ if(!ret){
+ vtblockput(b);
+ return -1;
+ }
+
+ vtentrypack(&e, b->data, f->offset % f->epb);
+ vtblockput(b);
+ return 0;
+}
+
+int
+vtfileflushbefore(VtFile *r, u64int offset)
+{
+ VtBlock *b, *bb;
+ VtEntry e;
+ int i, base, depth, ppb, epb, ok;
+ int index[VtPointerDepth+1], index1[VtPointerDepth+1], j, ret;
+ VtBlock *bi[VtPointerDepth+2];
+ uchar *score;
+
+ assert(ISLOCKED(r));
+ if(offset == 0)
+ return 0;
+
+ b = fileload(r, &e);
+ if(b == nil)
+ return -1;
+
+ ret = -1;
+ memset(bi, 0, sizeof bi);
+ depth = DEPTH(e.type);
+ bi[depth+1] = b;
+ i = mkindices(&e, (offset-1)/e.dsize, index);
+ if(i < 0)
+ goto Err;
+ if(i > depth)
+ goto Err;
+ mkindices(&e, offset/e.dsize, index1);
+ ppb = e.psize / VtScoreSize;
+ epb = e.dsize / VtEntrySize;
+
+ index[depth] = r->offset % r->epb;
+ for(i=depth; i>=0; i--){
+ bb = blockwalk(b, index[i], r->c, VtORDWR, &e);
+ if(bb == nil)
+ goto Err;
+ bi[i] = bb;
+ b = bb;
+ }
+ ret = 0;
+
+ base = e.type&~VtTypeDepthMask;
+ for(i=0; i<depth; i++){
+ if(i == 0){
+ /* bottom: data or dir block */
+ ok = offset%e.dsize == 0;
+ }else{
+ /* middle: pointer blocks */
+ b = bi[i];
+ /*
+ * flush everything up to the break
+ */
+ for(j=0; j<index[i-1]; j++)
+ if(flushblock(r->c, nil, b->data+j*VtScoreSize, ppb, epb, base+i-1) < 0)
+ goto Err;
+ /*
+ * if the rest of the block is already flushed,
+ * we can flush the whole block.
+ */
+ ok = 1;
+ for(; j<ppb; j++)
+ if(vtglobaltolocal(b->data+j*VtScoreSize) != NilBlock)
+ ok = 0;
+ }
+ if(ok){
+ if(i == depth)
+ score = e.score;
+ else
+ score = bi[i+1]->data+index[i]*VtScoreSize;
+ if(flushblock(r->c, bi[i], score, ppb, epb, base+i) < 0)
+ goto Err;
+ }
+ }
+
+Err:
+ /* top: entry. do this always so that the score is up-to-date */
+ vtentrypack(&e, bi[depth+1]->data, index[depth]);
+ for(i=0; i<nelem(bi); i++)
+ if(bi[i])
+ vtblockput(bi[i]);
+ return ret;
+}
(DIR) diff --git a/src/libventi/hangup.c b/src/libventi/hangup.c
t@@ -0,0 +1,22 @@
+#include <u.h>
+#include <libc.h>
+#include <venti.h>
+#include "queue.h"
+
+void
+vthangup(VtConn *z)
+{
+ qlock(&z->lk);
+ z->state = VtStateClosed;
+ if(z->infd >= 0)
+ close(z->infd);
+ if(z->outfd >= 0 && z->outfd != z->infd)
+ close(z->outfd);
+ z->infd = -1;
+ z->outfd = -1;
+ if(z->writeq)
+ _vtqhangup(z->writeq);
+ if(z->readq)
+ _vtqhangup(z->readq);
+ qunlock(&z->lk);
+}
(DIR) diff --git a/src/libventi/mem.c b/src/libventi/mem.c
t@@ -0,0 +1,87 @@
+#include <u.h>
+#include <libc.h>
+#include <venti.h>
+
+enum {
+ IdealAlignment = 32,
+ ChunkSize = 128*1024,
+};
+
+
+void
+vtfree(void *p)
+{
+ if(p == 0)
+ return;
+ free(p);
+}
+
+void *
+vtmalloc(int size)
+{
+ void *p;
+
+ p = malloc(size);
+ if(p == 0)
+ sysfatal("vtmalloc: out of memory");
+ setmalloctag(p, getcallerpc(&size));
+ return p;
+}
+
+void *
+vtmallocz(int size)
+{
+ void *p = vtmalloc(size);
+ memset(p, 0, size);
+ setmalloctag(p, getcallerpc(&size));
+ return p;
+}
+
+void *
+vtrealloc(void *p, int size)
+{
+ if(p == nil)
+ return vtmalloc(size);
+ p = realloc(p, size);
+ if(p == 0)
+ sysfatal("vtMemRealloc: out of memory");
+ setrealloctag(p, getcallerpc(&size));
+ return p;
+}
+
+void *
+vtbrk(int n)
+{
+ static Lock lk;
+ static uchar *buf;
+ static int nbuf;
+ static int nchunk;
+ int align, pad;
+ void *p;
+
+ if(n >= IdealAlignment)
+ align = IdealAlignment;
+ else if(n > 8)
+ align = 8;
+ else
+ align = 4;
+
+ lock(&lk);
+ pad = (align - (ulong)buf) & (align-1);
+ if(n + pad > nbuf) {
+ buf = vtmallocz(ChunkSize);
+ nbuf = ChunkSize;
+ pad = (align - (ulong)buf) & (align-1);
+ nchunk++;
+ }
+
+ assert(n + pad <= nbuf);
+
+ p = buf + pad;
+ buf += pad + n;
+ nbuf -= pad + n;
+ unlock(&lk);
+
+ return p;
+}
+
(DIR) diff --git a/src/libventi/mkfile b/src/libventi/mkfile
t@@ -0,0 +1,42 @@
+PLAN9=../..
+<$PLAN9/src/mkhdr
+
+LIB=libventi.a
+
+OFILES=\
+ cache.$O\
+ client.$O\
+ conn.$O\
+ dial.$O\
+ debug.$O\
+ dtype.$O\
+ entry.$O\
+ fcall.$O\
+ fcallfmt.$O\
+ file.$O\
+ hangup.$O\
+ mem.$O\
+ packet.$O\
+ queue.$O\
+ root.$O\
+ rpc.$O\
+ scorefmt.$O\
+ send.$O\
+ server.$O\
+ srvhello.$O\
+ strdup.$O\
+ string.$O\
+ version.$O\
+ zero.$O\
+ zeroscore.$O\
+
+HFILES=\
+ $PLAN9/include/venti.h\
+
+<$PLAN9/src/mksyslib
+
+send.$O: queue.h
+server.$O: queue.h
+queue.$O: queue.h
+
+
(DIR) diff --git a/src/libventi/packet.c b/src/libventi/packet.c
t@@ -0,0 +1,941 @@
+#include <u.h>
+#include <libc.h>
+#include <venti.h>
+#include <libsec.h>
+
+typedef struct Mem Mem;
+typedef struct Frag Frag;
+
+enum {
+ BigMemSize = MaxFragSize,
+ SmallMemSize = BigMemSize/8,
+ NLocalFrag = 2,
+};
+
+/* position to carve out of a Mem */
+enum {
+ PFront,
+ PMiddle,
+ PEnd,
+};
+
+struct Mem
+{
+ Lock lk;
+ int ref;
+ uchar *bp;
+ uchar *ep;
+ uchar *rp;
+ uchar *wp;
+ Mem *next;
+};
+
+enum {
+ FragLocalFree,
+ FragLocalAlloc,
+ FragGlobal,
+};
+
+struct Frag
+{
+ int state;
+ Mem *mem;
+ uchar *rp;
+ uchar *wp;
+ Frag *next;
+ void (*free)(void*);
+ void *a;
+};
+
+struct Packet
+{
+ int size;
+ int asize; /* allocated memory - greater than size unless foreign frags */
+
+ Packet *next;
+
+ Frag *first;
+ Frag *last;
+
+ Frag local[NLocalFrag];
+};
+
+static Frag *fragalloc(Packet*, int n, int pos, Frag *next);
+static Frag *fragdup(Packet*, Frag*);
+static void fragfree(Frag*);
+
+static Mem *memalloc(int, int);
+static void memfree(Mem*);
+static int memhead(Mem *m, uchar *rp, int n);
+static int memtail(Mem *m, uchar *wp, int n);
+
+static char EPacketSize[] = "bad packet size";
+static char EPacketOffset[] = "bad packet offset";
+static char EBadSize[] = "bad size";
+
+static struct {
+ Lock lk;
+ Packet *packet;
+ int npacket;
+ Frag *frag;
+ int nfrag;
+ Mem *bigmem;
+ int nbigmem;
+ Mem *smallmem;
+ int nsmallmem;
+} freelist;
+
+#define FRAGSIZE(f) ((f)->wp - (f)->rp)
+#define FRAGASIZE(f) ((f)->mem ? (f)->mem->ep - (f)->mem->bp : 0)
+
+#define NOTFREE(p) assert((p)->size>=0)
+
+Packet *
+packetalloc(void)
+{
+ Packet *p;
+
+ lock(&freelist.lk);
+ p = freelist.packet;
+ if(p != nil)
+ freelist.packet = p->next;
+ else
+ freelist.npacket++;
+ unlock(&freelist.lk);
+
+ if(p == nil)
+ p = vtbrk(sizeof(Packet));
+ else
+ assert(p->size == -1);
+ p->size = 0;
+ p->asize = 0;
+ p->first = nil;
+ p->last = nil;
+ p->next = nil;
+
+if(1)fprint(2, "packetalloc %p from %08lux %08lux %08lux\n", p, *((uint*)&p+2), *((uint*)&p+3), *((uint*)&p+4));
+
+ return p;
+}
+
+void
+packetfree(Packet *p)
+{
+ Frag *f, *ff;
+
+if(1)fprint(2, "packetfree %p from %08lux\n", p, getcallerpc(&p));
+
+ if(p == nil)
+ return;
+
+ NOTFREE(p);
+ p->size = -1;
+
+ for(f=p->first; f!=nil; f=ff) {
+ ff = f->next;
+ fragfree(f);
+ }
+ p->first = nil;
+ p->last = nil;
+
+ lock(&freelist.lk);
+ p->next = freelist.packet;
+ freelist.packet = p;
+ unlock(&freelist.lk);
+}
+
+Packet *
+packetdup(Packet *p, int offset, int n)
+{
+ Frag *f, *ff;
+ Packet *pp;
+
+ NOTFREE(p);
+ if(offset < 0 || n < 0 || offset+n > p->size) {
+ werrstr(EBadSize);
+ return nil;
+ }
+
+ pp = packetalloc();
+ if(n == 0)
+ return pp;
+
+ pp->size = n;
+
+ /* skip offset */
+ for(f=p->first; offset >= FRAGSIZE(f); f=f->next)
+ offset -= FRAGSIZE(f);
+
+ /* first frag */
+ ff = fragdup(pp, f);
+ ff->rp += offset;
+ pp->first = ff;
+ n -= FRAGSIZE(ff);
+ pp->asize += FRAGASIZE(ff);
+
+ /* the remaining */
+ while(n > 0) {
+ f = f->next;
+ ff->next = fragdup(pp, f);
+ ff = ff->next;
+ n -= FRAGSIZE(ff);
+ pp->asize += FRAGASIZE(ff);
+ }
+
+ /* fix up last frag: note n <= 0 */
+ ff->wp += n;
+ ff->next = nil;
+ pp->last = ff;
+
+ return pp;
+}
+
+Packet *
+packetsplit(Packet *p, int n)
+{
+ Packet *pp;
+ Frag *f, *ff;
+
+ NOTFREE(p);
+ if(n < 0 || n > p->size) {
+ werrstr(EPacketSize);
+ return nil;
+ }
+
+ pp = packetalloc();
+ if(n == 0)
+ return pp;
+
+ pp->size = n;
+ p->size -= n;
+ ff = nil;
+ for(f=p->first; n > 0 && n >= FRAGSIZE(f); f=f->next) {
+ n -= FRAGSIZE(f);
+ p->asize -= FRAGASIZE(f);
+ pp->asize += FRAGASIZE(f);
+ ff = f;
+ }
+
+ /* split shared frag */
+ if(n > 0) {
+ ff = f;
+ f = fragdup(pp, ff);
+ pp->asize += FRAGASIZE(ff);
+ ff->next = nil;
+ ff->wp = ff->rp + n;
+ f->rp += n;
+ }
+
+ pp->first = p->first;
+ pp->last = ff;
+ p->first = f;
+ return pp;
+}
+
+int
+packetconsume(Packet *p, uchar *buf, int n)
+{
+ NOTFREE(p);
+ if(buf && packetcopy(p, buf, 0, n) < 0)
+ return 0;
+ return packettrim(p, n, p->size-n);
+}
+
+int
+packettrim(Packet *p, int offset, int n)
+{
+ Frag *f, *ff;
+
+ NOTFREE(p);
+ if(offset < 0 || offset > p->size) {
+ werrstr(EPacketOffset);
+ return -1;
+ }
+
+ if(n < 0 || offset + n > p->size) {
+ werrstr(EPacketOffset);
+ return -1;
+ }
+
+ p->size = n;
+
+ /* easy case */
+ if(n == 0) {
+ for(f=p->first; f != nil; f=ff) {
+ ff = f->next;
+ fragfree(f);
+ }
+ p->first = p->last = nil;
+ p->asize = 0;
+ return 0;
+ }
+
+ /* free before offset */
+ for(f=p->first; offset >= FRAGSIZE(f); f=ff) {
+ p->asize -= FRAGASIZE(f);
+ offset -= FRAGSIZE(f);
+ ff = f->next;
+ fragfree(f);
+ }
+
+ /* adjust frag */
+ f->rp += offset;
+ p->first = f;
+
+ /* skip middle */
+ for(; n > 0 && n > FRAGSIZE(f); f=f->next)
+ n -= FRAGSIZE(f);
+
+ /* adjust end */
+ f->wp = f->rp + n;
+ p->last = f;
+ ff = f->next;
+ f->next = nil;
+
+ /* free after */
+ for(f=ff; f != nil; f=ff) {
+ p->asize -= FRAGASIZE(f);
+ ff = f->next;
+ fragfree(f);
+ }
+ return 0;
+}
+
+uchar *
+packetheader(Packet *p, int n)
+{
+ Frag *f;
+ Mem *m;
+
+ NOTFREE(p);
+ if(n <= 0 || n > MaxFragSize) {
+ werrstr(EPacketSize);
+ return nil;
+ }
+
+ p->size += n;
+
+ /* try and fix in current frag */
+ f = p->first;
+ if(f != nil) {
+ m = f->mem;
+ if(n <= f->rp - m->bp)
+ if(m->ref == 1 || memhead(m, f->rp, n) >= 0) {
+ f->rp -= n;
+ return f->rp;
+ }
+ }
+
+ /* add frag to front */
+ f = fragalloc(p, n, PEnd, p->first);
+ p->asize += FRAGASIZE(f);
+ if(p->first == nil)
+ p->last = f;
+ p->first = f;
+ return f->rp;
+}
+
+uchar *
+packettrailer(Packet *p, int n)
+{
+ Mem *m;
+ Frag *f;
+
+ NOTFREE(p);
+ if(n <= 0 || n > MaxFragSize) {
+ werrstr(EPacketSize);
+ return nil;
+ }
+
+ p->size += n;
+
+ /* try and fix in current frag */
+ if(p->first != nil) {
+ f = p->last;
+ m = f->mem;
+ if(n <= m->ep - f->wp)
+ if(m->ref == 1 || memtail(m, f->wp, n) >= 0) {
+ f->wp += n;
+ return f->wp - n;
+ }
+ }
+
+ /* add frag to end */
+ f = fragalloc(p, n, (p->first == nil)?PMiddle:PFront, nil);
+ p->asize += FRAGASIZE(f);
+ if(p->first == nil)
+ p->first = f;
+ else
+ p->last->next = f;
+ p->last = f;
+ return f->rp;
+}
+
+int
+packetprefix(Packet *p, uchar *buf, int n)
+{
+ Frag *f;
+ int nn;
+ Mem *m;
+
+ NOTFREE(p);
+ if(n <= 0)
+ return 0;
+
+ p->size += n;
+
+ /* try and fix in current frag */
+ f = p->first;
+ if(f != nil) {
+ m = f->mem;
+ nn = f->rp - m->bp;
+ if(nn > n)
+ nn = n;
+ if(m->ref == 1 || memhead(m, f->rp, nn) >= 0) {
+ f->rp -= nn;
+ n -= nn;
+ memmove(f->rp, buf+n, nn);
+ }
+ }
+
+ while(n > 0) {
+ nn = n;
+ if(nn > MaxFragSize)
+ nn = MaxFragSize;
+ f = fragalloc(p, nn, PEnd, p->first);
+ p->asize += FRAGASIZE(f);
+ if(p->first == nil)
+ p->last = f;
+ p->first = f;
+ n -= nn;
+ memmove(f->rp, buf+n, nn);
+ }
+ return 0;
+}
+
+int
+packetappend(Packet *p, uchar *buf, int n)
+{
+ Frag *f;
+ int nn;
+ Mem *m;
+
+ NOTFREE(p);
+ if(n <= 0)
+ return 0;
+
+ p->size += n;
+ /* try and fix in current frag */
+ if(p->first != nil) {
+ f = p->last;
+ m = f->mem;
+ nn = m->ep - f->wp;
+ if(nn > n)
+ nn = n;
+ if(m->ref == 1 || memtail(m, f->wp, nn) >= 0) {
+ memmove(f->wp, buf, nn);
+ f->wp += nn;
+ buf += nn;
+ n -= nn;
+ }
+ }
+
+ while(n > 0) {
+ nn = n;
+ if(nn > MaxFragSize)
+ nn = MaxFragSize;
+ f = fragalloc(p, nn, (p->first == nil)?PMiddle:PFront, nil);
+ p->asize += FRAGASIZE(f);
+ if(p->first == nil)
+ p->first = f;
+ else
+ p->last->next = f;
+ p->last = f;
+ memmove(f->rp, buf, nn);
+ buf += nn;
+ n -= nn;
+ }
+ return 0;
+}
+
+int
+packetconcat(Packet *p, Packet *pp)
+{
+ NOTFREE(p);
+ NOTFREE(pp);
+ if(pp->size == 0)
+ return 0;
+ p->size += pp->size;
+ p->asize += pp->asize;
+
+ if(p->first != nil)
+ p->last->next = pp->first;
+ else
+ p->first = pp->first;
+ p->last = pp->last;
+ pp->size = 0;
+ pp->asize = 0;
+ pp->first = nil;
+ pp->last = nil;
+ return 0;
+}
+
+uchar *
+packetpeek(Packet *p, uchar *buf, int offset, int n)
+{
+ Frag *f;
+ int nn;
+ uchar *b;
+
+ NOTFREE(p);
+ if(n == 0)
+ return buf;
+
+ if(offset < 0 || offset >= p->size) {
+ werrstr(EPacketOffset);
+ return nil;
+ }
+
+ if(n < 0 || offset + n > p->size) {
+ werrstr(EPacketSize);
+ return nil;
+ }
+
+ /* skip up to offset */
+ for(f=p->first; offset >= FRAGSIZE(f); f=f->next)
+ offset -= FRAGSIZE(f);
+
+ /* easy case */
+ if(offset + n <= FRAGSIZE(f))
+ return f->rp + offset;
+
+ for(b=buf; n>0; n -= nn) {
+ nn = FRAGSIZE(f) - offset;
+ if(nn > n)
+ nn = n;
+ memmove(b, f->rp+offset, nn);
+ offset = 0;
+ f = f->next;
+ b += nn;
+ }
+
+ return buf;
+}
+
+int
+packetcopy(Packet *p, uchar *buf, int offset, int n)
+{
+ uchar *b;
+
+ NOTFREE(p);
+ b = packetpeek(p, buf, offset, n);
+ if(b == nil)
+ return -1;
+ if(b != buf)
+ memmove(buf, b, n);
+ return 0;
+}
+
+int
+packetfragments(Packet *p, IOchunk *io, int nio, int offset)
+{
+ Frag *f;
+ int size;
+ IOchunk *eio;
+
+ NOTFREE(p);
+ if(p->size == 0 || nio <= 0)
+ return 0;
+
+ if(offset < 0 || offset > p->size) {
+ werrstr(EPacketOffset);
+ return -1;
+ }
+
+ for(f=p->first; offset >= FRAGSIZE(f); f=f->next)
+ offset -= FRAGSIZE(f);
+
+ size = 0;
+ eio = io + nio;
+ for(; f != nil && io < eio; f=f->next) {
+ io->addr = f->rp + offset;
+ io->len = f->wp - (f->rp + offset);
+ offset = 0;
+ size += io->len;
+ io++;
+ }
+
+ return size;
+}
+
+void
+packetstats(void)
+{
+ Packet *p;
+ Frag *f;
+ Mem *m;
+
+ int np, nf, nsm, nbm;
+
+ lock(&freelist.lk);
+ np = 0;
+ for(p=freelist.packet; p; p=p->next)
+ np++;
+ nf = 0;
+ for(f=freelist.frag; f; f=f->next)
+ nf++;
+ nsm = 0;
+ for(m=freelist.smallmem; m; m=m->next)
+ nsm++;
+ nbm = 0;
+ for(m=freelist.bigmem; m; m=m->next)
+ nbm++;
+
+ fprint(2, "packet: %d/%d frag: %d/%d small mem: %d/%d big mem: %d/%d\n",
+ np, freelist.npacket,
+ nf, freelist.nfrag,
+ nsm, freelist.nsmallmem,
+ nbm, freelist.nbigmem);
+
+ unlock(&freelist.lk);
+}
+
+
+uint
+packetsize(Packet *p)
+{
+ NOTFREE(p);
+ if(0) {
+ Frag *f;
+ int size = 0;
+
+ for(f=p->first; f; f=f->next)
+ size += FRAGSIZE(f);
+ if(size != p->size)
+ fprint(2, "packetsize %d %d\n", size, p->size);
+ assert(size == p->size);
+ }
+ return p->size;
+}
+
+uint
+packetasize(Packet *p)
+{
+ NOTFREE(p);
+ if(0) {
+ Frag *f;
+ int asize = 0;
+
+ for(f=p->first; f; f=f->next)
+ asize += FRAGASIZE(f);
+ if(asize != p->asize)
+ fprint(2, "packetasize %d %d\n", asize, p->asize);
+ assert(asize == p->asize);
+ }
+ return p->asize;
+}
+
+void
+packetsha1(Packet *p, uchar digest[VtScoreSize])
+{
+ DigestState ds;
+ Frag *f;
+ int size;
+
+ NOTFREE(p);
+ memset(&ds, 0, sizeof ds);
+ size = p->size;
+ for(f=p->first; f; f=f->next) {
+ sha1(f->rp, FRAGSIZE(f), nil, &ds);
+ size -= FRAGSIZE(f);
+ }
+ assert(size == 0);
+ sha1(nil, 0, digest, &ds);
+}
+
+int
+packetcmp(Packet *pkt0, Packet *pkt1)
+{
+ Frag *f0, *f1;
+ int n0, n1, x;
+
+ NOTFREE(pkt0);
+ NOTFREE(pkt1);
+ f0 = pkt0->first;
+ f1 = pkt1->first;
+
+ if(f0 == nil)
+ return (f1 == nil)?0:-1;
+ if(f1 == nil)
+ return 1;
+ n0 = FRAGSIZE(f0);
+ n1 = FRAGSIZE(f1);
+
+ for(;;) {
+ if(n0 < n1) {
+ x = memcmp(f0->wp - n0, f1->wp - n1, n0);
+ if(x != 0)
+ return x;
+ n1 -= n0;
+ f0 = f0->next;
+ if(f0 == nil)
+ return -1;
+ n0 = FRAGSIZE(f0);
+ } else if (n0 > n1) {
+ x = memcmp(f0->wp - n0, f1->wp - n1, n1);
+ if(x != 0)
+ return x;
+ n0 -= n1;
+ f1 = f1->next;
+ if(f1 == nil)
+ return 1;
+ n1 = FRAGSIZE(f1);
+ } else { /* n0 == n1 */
+ x = memcmp(f0->wp - n0, f1->wp - n1, n0);
+ if(x != 0)
+ return x;
+ f0 = f0->next;
+ f1 = f1->next;
+ if(f0 == nil)
+ return (f1 == nil)?0:-1;
+ if(f1 == nil)
+ return 1;
+ n0 = FRAGSIZE(f0);
+ n1 = FRAGSIZE(f1);
+ }
+ }
+ return 0; /* for ken */
+}
+
+
+static Frag *
+fragalloc(Packet *p, int n, int pos, Frag *next)
+{
+ Frag *f, *ef;
+ Mem *m;
+
+ /* look for local frag */
+ f = &p->local[0];
+ ef = &p->local[NLocalFrag];
+ for(;f<ef; f++) {
+ if(f->state == FragLocalFree) {
+ f->state = FragLocalAlloc;
+ goto Found;
+ }
+ }
+ lock(&freelist.lk);
+ f = freelist.frag;
+ if(f != nil)
+ freelist.frag = f->next;
+ else
+ freelist.nfrag++;
+ unlock(&freelist.lk);
+
+ if(f == nil) {
+ f = vtbrk(sizeof(Frag));
+ f->state = FragGlobal;
+ }
+
+Found:
+ f->next = next;
+
+ if(n == 0){
+ f->mem = 0;
+ f->rp = 0;
+ f->wp = 0;
+ return f;
+ }
+
+ if(pos == PEnd && next == nil)
+ pos = PMiddle;
+ m = memalloc(n, pos);
+ f->mem = m;
+ f->rp = m->rp;
+ f->wp = m->wp;
+ return f;
+}
+
+Packet*
+packetforeign(uchar *buf, int n, void (*free)(void *a), void *a)
+{
+ Packet *p;
+ Frag *f;
+
+ p = packetalloc();
+ f = fragalloc(p, 0, 0, nil);
+ f->free = free;
+ f->a = a;
+ f->next = nil;
+ f->rp = buf;
+ f->wp = buf+n;
+
+ p->first = f;
+ p->size = n;
+ return p;
+}
+
+static Frag *
+fragdup(Packet *p, Frag *f)
+{
+ Frag *ff;
+ Mem *m;
+
+ m = f->mem;
+
+ /*
+ * m->rp && m->wp can be out of date when ref == 1
+ * also, potentially reclaims space from previous frags
+ */
+ if(m && m->ref == 1) {
+ m->rp = f->rp;
+ m->wp = f->wp;
+ }
+
+ ff = fragalloc(p, 0, 0, nil);
+ *ff = *f;
+ if(m){
+ lock(&m->lk);
+ m->ref++;
+ unlock(&m->lk);
+ }
+ return ff;
+}
+
+
+static void
+fragfree(Frag *f)
+{
+ if(f->mem == nil){
+ if(f->free)
+ (*f->free)(f->a);
+ }else{
+ memfree(f->mem);
+ f->mem = 0;
+ }
+
+ if(f->state == FragLocalAlloc) {
+ f->state = FragLocalFree;
+ return;
+ }
+
+ lock(&freelist.lk);
+ f->next = freelist.frag;
+ freelist.frag = f;
+ unlock(&freelist.lk);
+}
+
+static Mem *
+memalloc(int n, int pos)
+{
+ Mem *m;
+ int nn;
+
+ if(n < 0 || n > MaxFragSize) {
+ werrstr(EPacketSize);
+ return 0;
+ }
+ if(n <= SmallMemSize) {
+ lock(&freelist.lk);
+ m = freelist.smallmem;
+ if(m != nil)
+ freelist.smallmem = m->next;
+ else
+ freelist.nsmallmem++;
+ unlock(&freelist.lk);
+ nn = SmallMemSize;
+ } else {
+ lock(&freelist.lk);
+ m = freelist.bigmem;
+ if(m != nil)
+ freelist.bigmem = m->next;
+ else
+ freelist.nbigmem++;
+ unlock(&freelist.lk);
+ nn = BigMemSize;
+ }
+
+ if(m == nil) {
+ m = vtbrk(sizeof(Mem));
+ m->bp = vtbrk(nn);
+ m->ep = m->bp + nn;
+ }
+ assert(m->ref == 0);
+ m->ref = 1;
+
+ switch(pos) {
+ default:
+ assert(0);
+ case PFront:
+ m->rp = m->bp;
+ break;
+ case PMiddle:
+ /* leave a little bit at end */
+ m->rp = m->ep - n - 32;
+ break;
+ case PEnd:
+ m->rp = m->ep - n;
+ break;
+ }
+ /* check we did not blow it */
+ if(m->rp < m->bp)
+ m->rp = m->bp;
+ m->wp = m->rp + n;
+ assert(m->rp >= m->bp && m->wp <= m->ep);
+ return m;
+}
+
+static void
+memfree(Mem *m)
+{
+ lock(&m->lk);
+ m->ref--;
+ if(m->ref > 0) {
+ unlock(&m->lk);
+ return;
+ }
+ unlock(&m->lk);
+ assert(m->ref == 0);
+
+ switch(m->ep - m->bp) {
+ default:
+ assert(0);
+ case SmallMemSize:
+ lock(&freelist.lk);
+ m->next = freelist.smallmem;
+ freelist.smallmem = m;
+ unlock(&freelist.lk);
+ break;
+ case BigMemSize:
+ lock(&freelist.lk);
+ m->next = freelist.bigmem;
+ freelist.bigmem = m;
+ unlock(&freelist.lk);
+ break;
+ }
+}
+
+static int
+memhead(Mem *m, uchar *rp, int n)
+{
+ lock(&m->lk);
+ if(m->rp != rp) {
+ unlock(&m->lk);
+ return -1;
+ }
+ m->rp -= n;
+ unlock(&m->lk);
+ return 0;
+}
+
+static int
+memtail(Mem *m, uchar *wp, int n)
+{
+ lock(&m->lk);
+ if(m->wp != wp) {
+ unlock(&m->lk);
+ return -1;
+ }
+ m->wp += n;
+ unlock(&m->lk);
+ return 0;
+}
(DIR) diff --git a/src/libventi/queue.c b/src/libventi/queue.c
t@@ -0,0 +1,103 @@
+#include <u.h>
+#include <libc.h>
+#include <venti.h>
+#include "queue.h"
+
+typedef struct Qel Qel;
+struct Qel
+{
+ Qel *next;
+ void *p;
+};
+
+struct Queue
+{
+ int hungup;
+ QLock lk;
+ Rendez r;
+ Qel *head;
+ Qel *tail;
+};
+
+Queue*
+_vtqalloc(void)
+{
+ Queue *q;
+
+ q = vtmallocz(sizeof(Queue));
+ q->r.l = &q->lk;
+ return q;
+}
+
+int
+_vtqsend(Queue *q, void *p)
+{
+ Qel *e;
+
+ e = vtmalloc(sizeof(Qel));
+ qlock(&q->lk);
+ if(q->hungup){
+ werrstr("hungup queue");
+ qunlock(&q->lk);
+ return -1;
+ }
+ e->p = p;
+ e->next = nil;
+ if(q->head == nil)
+ q->head = e;
+ else
+ q->tail->next = e;
+ q->tail = e;
+ rwakeup(&q->r);
+ qunlock(&q->lk);
+ return 0;
+}
+
+void*
+_vtqrecv(Queue *q)
+{
+ void *p;
+ Qel *e;
+
+ qlock(&q->lk);
+ while(q->head == nil && !q->hungup)
+ rsleep(&q->r);
+ if(q->hungup){
+ qunlock(&q->lk);
+ return nil;
+ }
+ e = q->head;
+ q->head = e->next;
+ qunlock(&q->lk);
+ p = e->p;
+ vtfree(e);
+ return p;
+}
+
+void*
+_vtnbqrecv(Queue *q)
+{
+ void *p;
+ Qel *e;
+
+ qlock(&q->lk);
+ if(q->head == nil){
+ qunlock(&q->lk);
+ return nil;
+ }
+ e = q->head;
+ q->head = e->next;
+ qunlock(&q->lk);
+ p = e->p;
+ vtfree(e);
+ return p;
+}
+
+void
+_vtqhangup(Queue *q)
+{
+ qlock(&q->lk);
+ q->hungup = 1;
+ rwakeupall(&q->r);
+ qunlock(&q->lk);
+}
(DIR) diff --git a/src/libventi/queue.h b/src/libventi/queue.h
t@@ -0,0 +1,6 @@
+typedef struct Queue Queue;
+Queue *_vtqalloc(void);
+int _vtqsend(Queue*, void*);
+void *_vtqrecv(Queue*);
+void _vtqhangup(Queue*);
+void *_vtnbqrecv(Queue*);
(DIR) diff --git a/src/libventi/root.c b/src/libventi/root.c
t@@ -0,0 +1,67 @@
+#include <u.h>
+#include <libc.h>
+#include <venti.h>
+#include "cvt.h"
+
+static int
+checksize(int n)
+{
+ if(n < 256 || n > VtMaxLumpSize) {
+ werrstr("bad block size");
+ return -1;
+ }
+ return 0;
+}
+
+void
+vtrootpack(VtRoot *r, uchar *p)
+{
+ uchar *op = p;
+
+ U16PUT(p, VtRootVersion);
+ p += 2;
+ memmove(p, r->name, sizeof(r->name));
+ p += sizeof(r->name);
+ memmove(p, r->type, sizeof(r->type));
+ p += sizeof(r->type);
+ memmove(p, r->score, VtScoreSize);
+ p += VtScoreSize;
+ U16PUT(p, r->blocksize);
+ p += 2;
+ memmove(p, r->prev, VtScoreSize);
+ p += VtScoreSize;
+
+ assert(p-op == VtRootSize);
+}
+
+int
+vtrootunpack(VtRoot *r, uchar *p)
+{
+ uchar *op = p;
+ uint vers;
+ memset(r, 0, sizeof(*r));
+
+ vers = U16GET(p);
+ if(vers != VtRootVersion) {
+ werrstr("unknown root version");
+ return 0;
+ }
+ p += 2;
+ memmove(r->name, p, sizeof(r->name));
+ r->name[sizeof(r->name)-1] = 0;
+ p += sizeof(r->name);
+ memmove(r->type, p, sizeof(r->type));
+ r->type[sizeof(r->type)-1] = 0;
+ p += sizeof(r->type);
+ memmove(r->score, p, VtScoreSize);
+ p += VtScoreSize;
+ r->blocksize = U16GET(p);
+ if(checksize(r->blocksize) < 0)
+ return -1;
+ p += 2;
+ memmove(r->prev, p, VtScoreSize);
+ p += VtScoreSize;
+
+ assert(p-op == VtRootSize);
+ return 0;
+}
(DIR) diff --git a/src/libventi/rpc.c b/src/libventi/rpc.c
t@@ -0,0 +1,155 @@
+/*
+ * Multiplexed Venti client. It would be nice if we
+ * could turn this into a generic library routine rather
+ * than keep it Venti specific. A user-level 9P client
+ * could use something like this too.
+ *
+ * This is a little more complicated than it might be
+ * because we want it to work well within and without libthread.
+ *
+ * The mux code is inspired by tra's, which is inspired by the Plan 9 kernel.
+ */
+
+#include <u.h>
+#include <libc.h>
+#include <venti.h>
+
+typedef struct Rwait Rwait;
+struct Rwait
+{
+ Rendez r;
+ Packet *p;
+ int done;
+ int sleeping;
+};
+
+static int gettag(VtConn*, Rwait*);
+static void puttag(VtConn*, Rwait*, int);
+static void muxrpc(VtConn*, Packet*);
+Packet *vtrpc(VtConn*, Packet*);
+
+Packet*
+vtrpc(VtConn *z, Packet *p)
+{
+ int i;
+ uchar tag, buf[2], *top;
+ Rwait *r;
+
+ /* must malloc because stack could be private */
+ r = vtmallocz(sizeof(Rwait));
+
+ qlock(&z->lk);
+ r->r.l = &z->lk;
+ tag = gettag(z, r);
+
+ /* slam tag into packet */
+ top = packetpeek(p, buf, 0, 2);
+ if(top == nil){
+ packetfree(p);
+ return nil;
+ }
+ if(top == buf){
+ werrstr("first two bytes must be in same packet fragment");
+ packetfree(p);
+ return nil;
+ }
+ top[1] = tag;
+ qunlock(&z->lk);
+ if(vtsend(z, p) < 0)
+ return nil;
+
+ qlock(&z->lk);
+ /* wait for the muxer to give us our packet */
+ r->sleeping = 1;
+ z->nsleep++;
+ while(z->muxer && !r->done)
+ rsleep(&r->r);
+ z->nsleep--;
+ r->sleeping = 0;
+
+ /* if not done, there's no muxer: start muxing */
+ if(!r->done){
+ if(z->muxer)
+ abort();
+ z->muxer = 1;
+ while(!r->done){
+ qunlock(&z->lk);
+ if((p = vtrecv(z)) == nil){
+ z->muxer = 0;
+ return nil;
+ }
+ qlock(&z->lk);
+ muxrpc(z, p);
+ }
+ z->muxer = 0;
+ /* if there is anyone else sleeping, wake them to mux */
+ if(z->nsleep){
+ for(i=0; i<256; i++)
+ if(z->wait[i] != nil && ((Rwait*)z->wait[i])->sleeping)
+ break;
+ if(i==256)
+ fprint(2, "libventi: nsleep botch\n");
+ else
+ rwakeup(&((Rwait*)z->wait[i])->r);
+ }
+ }
+
+ p = r->p;
+ puttag(z, r, tag);
+ vtfree(r);
+ qunlock(&z->lk);
+ return p;
+}
+
+static int
+gettag(VtConn *z, Rwait *r)
+{
+ int i;
+
+Again:
+ while(z->ntag == 256)
+ rsleep(&z->tagrend);
+ for(i=0; i<256; i++)
+ if(z->wait[i] == 0){
+ z->ntag++;
+ z->wait[i] = r;
+ return i;
+ }
+ fprint(2, "libventi: ntag botch\n");
+ goto Again;
+}
+
+static void
+puttag(VtConn *z, Rwait *r, int tag)
+{
+ assert(z->wait[tag] == r);
+ z->wait[tag] = nil;
+ z->ntag--;
+ rwakeup(&z->tagrend);
+}
+
+static void
+muxrpc(VtConn *z, Packet *p)
+{
+ uchar tag, buf[2], *top;
+ Rwait *r;
+
+ if((top = packetpeek(p, buf, 0, 2)) == nil){
+ fprint(2, "libventi: short packet in vtrpc\n");
+ packetfree(p);
+ return;
+ }
+
+ tag = top[1];
+ if((r = z->wait[tag]) == nil){
+ fprint(2, "libventi: unexpected packet tag %d in vtrpc\n", tag);
+abort();
+ packetfree(p);
+ return;
+ }
+
+ r->p = p;
+ r->done = 1;
+ rwakeup(&r->r);
+}
+
(DIR) diff --git a/src/libventi/scorefmt.c b/src/libventi/scorefmt.c
t@@ -0,0 +1,18 @@
+#include <u.h>
+#include <libc.h>
+#include <venti.h>
+
+int
+vtscorefmt(Fmt *f)
+{
+ uchar *v;
+ int i;
+
+ v = va_arg(f->args, uchar*);
+ if(v == nil)
+ fmtprint(f, "*");
+ else
+ for(i = 0; i < VtScoreSize; i++)
+ fmtprint(f, "%2.2ux", v[i]);
+ return 0;
+}
(DIR) diff --git a/src/libventi/send.c b/src/libventi/send.c
t@@ -0,0 +1,212 @@
+#include <u.h>
+#include <libc.h>
+#include <venti.h>
+#include "queue.h"
+
+static int
+_vtsend(VtConn *z, Packet *p)
+{
+ IOchunk ioc;
+ int n;
+ uchar buf[2];
+
+ if(z->state != VtStateConnected) {
+ werrstr("session not connected");
+ return -1;
+ }
+
+ /* add framing */
+ n = packetsize(p);
+ if(n >= (1<<16)) {
+ werrstr("packet too large");
+ packetfree(p);
+ return -1;
+ }
+ buf[0] = n>>8;
+ buf[1] = n;
+ packetprefix(p, buf, 2);
+
+ for(;;){
+ n = packetfragments(p, &ioc, 1, 0);
+ if(n == 0)
+ break;
+ if(write(z->outfd, ioc.addr, ioc.len) < ioc.len){
+ packetfree(p);
+ return 0;
+ }
+ packetconsume(p, nil, ioc.len);
+ }
+ packetfree(p);
+ return 1;
+}
+
+static Packet*
+_vtrecv(VtConn *z)
+{
+ uchar buf[10], *b;
+ int n;
+ Packet *p;
+ int size, len;
+
+ if(z->state != VtStateConnected) {
+ werrstr("session not connected");
+ return nil;
+ }
+
+ p = z->part;
+ /* get enough for head size */
+ size = packetsize(p);
+ while(size < 2) {
+ b = packettrailer(p, MaxFragSize);
+ assert(b != nil);
+ n = read(z->infd, b, MaxFragSize);
+ if(n <= 0)
+ goto Err;
+ size += n;
+ packettrim(p, 0, size);
+ }
+
+ if(packetconsume(p, buf, 2) < 0)
+ goto Err;
+ len = (buf[0] << 8) | buf[1];
+ size -= 2;
+
+ while(size < len) {
+ n = len - size;
+ if(n > MaxFragSize)
+ n = MaxFragSize;
+ b = packettrailer(p, n);
+ if(readn(z->infd, b, n) != n)
+ goto Err;
+ size += n;
+ }
+ p = packetsplit(p, len);
+ return p;
+Err:
+ return nil;
+}
+
+/*
+ * If you fork off two procs running vtrecvproc and vtsendproc,
+ * then vtrecv/vtsend (and thus vtrpc) will never block except on
+ * rendevouses, which is nice when it's running in one thread of many.
+ */
+void
+vtrecvproc(void *v)
+{
+ Packet *p;
+ VtConn *z;
+ Queue *q;
+
+ z = v;
+ q = _vtqalloc();
+
+ qlock(&z->lk);
+ z->readq = q;
+ qlock(&z->inlk);
+ rwakeup(&z->rpcfork);
+ qunlock(&z->lk);
+
+ while((p = _vtrecv(z)) != nil)
+ if(_vtqsend(q, p) < 0){
+ packetfree(p);
+ break;
+ }
+ qunlock(&z->inlk);
+ qlock(&z->lk);
+ _vtqhangup(q);
+ while((p = _vtnbqrecv(q)) != nil)
+ packetfree(p);
+ vtfree(q);
+ z->readq = nil;
+ rwakeup(&z->rpcfork);
+ qunlock(&z->lk);
+ vthangup(z);
+}
+
+void
+vtsendproc(void *v)
+{
+ Queue *q;
+ Packet *p;
+ VtConn *z;
+
+ z = v;
+ q = _vtqalloc();
+
+ qlock(&z->lk);
+ z->writeq = q;
+ qlock(&z->outlk);
+ rwakeup(&z->rpcfork);
+ qunlock(&z->lk);
+
+ while((p = _vtqrecv(q)) != nil)
+ if(_vtsend(z, p) < 0)
+ break;
+ qunlock(&z->outlk);
+ qlock(&z->lk);
+ _vtqhangup(q);
+ while((p = _vtnbqrecv(q)) != nil)
+ packetfree(p);
+ vtfree(q);
+ z->writeq = nil;
+ rwakeup(&z->rpcfork);
+ qunlock(&z->lk);
+ return;
+}
+
+Packet*
+vtrecv(VtConn *z)
+{
+ Packet *p;
+
+ qlock(&z->lk);
+ if(z->state != VtStateConnected){
+ werrstr("not connected");
+ qunlock(&z->lk);
+ return nil;
+ }
+ if(z->readq){
+ qunlock(&z->lk);
+ return _vtqrecv(z->readq);
+ }
+
+ qlock(&z->inlk);
+ qunlock(&z->lk);
+ p = _vtrecv(z);
+ qunlock(&z->inlk);
+ if(!p)
+ vthangup(z);
+ return p;
+}
+
+int
+vtsend(VtConn *z, Packet *p)
+{
+ qlock(&z->lk);
+ if(z->state != VtStateConnected){
+ packetfree(p);
+ werrstr("not connected");
+ qunlock(&z->lk);
+ return -1;
+ }
+ if(z->writeq){
+ qunlock(&z->lk);
+ if(_vtqsend(z->writeq, p) < 0){
+ packetfree(p);
+ return -1;
+ }
+ return 0;
+ }
+
+ qlock(&z->outlk);
+ qunlock(&z->lk);
+ if(_vtsend(z, p) < 0){
+ qunlock(&z->outlk);
+ vthangup(z);
+ return -1;
+ }
+ qunlock(&z->outlk);
+ return 0;
+}
+
(DIR) diff --git a/src/libventi/server.c b/src/libventi/server.c
t@@ -0,0 +1,172 @@
+#include <u.h>
+#include <libc.h>
+#include <venti.h>
+#include <thread.h>
+#include "queue.h"
+
+enum
+{
+ STACK = 8192,
+};
+
+typedef struct VtSconn VtSconn;
+struct VtSconn
+{
+ int ctl;
+ char dir[NETPATHLEN];
+ VtSrv *srv;
+ VtConn *c;
+};
+
+struct VtSrv
+{
+ int afd;
+ int dead;
+ char adir[NETPATHLEN];
+ Queue *q; /* Queue(VtReq*) */
+};
+
+static void listenproc(void*);
+static void connproc(void*);
+
+VtSrv*
+vtlisten(char *addr)
+{
+ VtSrv *s;
+
+ s = vtmallocz(sizeof(VtSrv));
+ s->afd = announce(addr, s->adir);
+ if(s->afd < 0){
+ free(s);
+ return nil;
+ }
+ s->q = _vtqalloc();
+ proccreate(listenproc, s, STACK);
+ return s;
+}
+
+static void
+listenproc(void *v)
+{
+ int ctl;
+ char dir[NETPATHLEN];
+ VtSrv *srv;
+ VtSconn *sc;
+
+ srv = v;
+ for(;;){
+ ctl = listen(srv->adir, dir);
+ if(ctl < 0){
+ srv->dead = 1;
+ break;
+ }
+ sc = vtmallocz(sizeof(VtSconn));
+ sc->ctl = ctl;
+ sc->srv = srv;
+ strcpy(sc->dir, dir);
+ proccreate(connproc, sc, STACK);
+ }
+
+ // hangup
+}
+
+static void
+connproc(void *v)
+{
+ VtSconn *sc;
+ VtConn *c;
+ Packet *p;
+ VtReq *r;
+ int fd;
+
+ r = nil;
+ c = nil;
+ sc = v;
+ fprint(2, "new call %s on %d\n", sc->dir, sc->ctl);
+ fd = accept(sc->ctl, sc->dir);
+ close(sc->ctl);
+ if(fd < 0){
+ fprint(2, "accept %s: %r\n", sc->dir);
+ goto out;
+ }
+
+ c = vtconn(fd, fd);
+ sc->c = c;
+ if(vtversion(c) < 0){
+ fprint(2, "vtversion %s: %r\n", sc->dir);
+ goto out;
+ }
+ if(vtsrvhello(c) < 0){
+ fprint(2, "vtsrvhello %s: %r\n", sc->dir);
+ goto out;
+ }
+
+ fprint(2, "new proc %s\n", sc->dir);
+ proccreate(vtsendproc, c, STACK);
+ qlock(&c->lk);
+ while(!c->writeq)
+ rsleep(&c->rpcfork);
+ qunlock(&c->lk);
+
+ while((p = vtrecv(c)) != nil){
+ r = vtmallocz(sizeof(VtReq));
+ if(vtfcallunpack(&r->tx, p) < 0){
+ packetfree(p);
+ fprint(2, "bad packet on %s: %r\n", sc->dir);
+ continue;
+ }
+ packetfree(p);
+ if(r->tx.type == VtTgoodbye)
+ break;
+ r->rx.tag = r->tx.tag;
+ r->sc = sc;
+ if(_vtqsend(sc->srv->q, r) < 0){
+ fprint(2, "hungup queue\n");
+ break;
+ }
+ r = nil;
+ }
+
+ fprint(2, "eof on %s\n", sc->dir);
+
+out:
+ if(r){
+ vtfcallclear(&r->tx);
+ vtfree(r);
+ }
+ if(c)
+ vtfreeconn(c);
+ fprint(2, "freed %s\n", sc->dir);
+ vtfree(sc);
+ return;
+}
+
+VtReq*
+vtgetreq(VtSrv *srv)
+{
+ return _vtqrecv(srv->q);
+}
+
+void
+vtrespond(VtReq *r)
+{
+ Packet *p;
+ VtSconn *sc;
+
+ sc = r->sc;
+ if(r->rx.tag != r->tx.tag)
+ abort();
+ if(r->rx.type != r->tx.type+1 && r->rx.type != VtRerror)
+ abort();
+ if((p = vtfcallpack(&r->rx)) == nil){
+ fprint(2, "fcallpack on %s: %r\n", sc->dir);
+ packetfree(p);
+ vtfcallclear(&r->rx);
+ return;
+ }
+ vtsend(sc->c, p);
+ vtfcallclear(&r->tx);
+ vtfcallclear(&r->rx);
+ vtfree(r);
+}
+
(DIR) diff --git a/src/libventi/srvhello.c b/src/libventi/srvhello.c
t@@ -0,0 +1,50 @@
+#include <u.h>
+#include <libc.h>
+#include <venti.h>
+
+int
+vtsrvhello(VtConn *z)
+{
+ VtFcall tx, rx;
+ Packet *p;
+
+ if((p = vtrecv(z)) == nil)
+ return 0;
+
+ if(vtfcallunpack(&tx, p) < 0){
+ packetfree(p);
+ return 0;
+ }
+ packetfree(p);
+
+ if(tx.type != VtThello){
+ vtfcallclear(&tx);
+ werrstr("bad packet type %d; want Thello %d", tx.type, VtThello);
+ return 0;
+ }
+ if(tx.tag != 0){
+ vtfcallclear(&tx);
+ werrstr("bad tag in hello");
+ return 0;
+ }
+ if(strcmp(tx.version, z->version) != 0){
+ vtfcallclear(&tx);
+ werrstr("bad version in hello");
+ return 0;
+ }
+ vtfree(z->uid);
+ z->uid = tx.uid;
+ tx.uid = nil;
+ vtfcallclear(&tx);
+
+ memset(&rx, 0, sizeof rx);
+ rx.type = VtRhello;
+ rx.tag = tx.tag;
+ rx.sid = "anonymous";
+ if((p = vtfcallpack(&rx)) == nil)
+ return 0;
+ if(vtsend(z, p) < 0)
+ return 0;
+
+ return 1;
+}
(DIR) diff --git a/src/libventi/strdup.c b/src/libventi/strdup.c
t@@ -0,0 +1,18 @@
+#include <u.h>
+#include <libc.h>
+#include <venti.h>
+
+char*
+vtstrdup(char *s)
+{
+ int n;
+ char *ss;
+
+ if(s == nil)
+ return nil;
+ n = strlen(s) + 1;
+ ss = vtmalloc(n);
+ memmove(ss, s, n);
+ return ss;
+}
+
(DIR) diff --git a/src/libventi/string.c b/src/libventi/string.c
t@@ -0,0 +1,50 @@
+#include <u.h>
+#include <libc.h>
+#include <venti.h>
+
+int
+vtputstring(Packet *p, char *s)
+{
+ uchar buf[2];
+ int n;
+
+ if(s == nil){
+ werrstr("null string in packet");
+ return -1;
+ }
+ n = strlen(s);
+ if(n > VtMaxStringSize){
+ werrstr("string too long in packet");
+ return -1;
+ }
+ buf[0] = n>>8;
+ buf[1] = n;
+ packetappend(p, buf, 2);
+ packetappend(p, (uchar*)s, n);
+ return 0;
+}
+
+int
+vtgetstring(Packet *p, char **ps)
+{
+ uchar buf[2];
+ int n;
+ char *s;
+
+ if(packetconsume(p, buf, 2) < 0)
+ return -1;
+ n = (buf[0]<<8) + buf[1];
+ if(n > VtMaxStringSize) {
+ werrstr("string too long in packet");
+ return -1;
+ }
+ s = vtmalloc(n+1);
+ if(packetconsume(p, (uchar*)s, n) < 0){
+ vtfree(s);
+ return -1;
+ }
+ s[n] = 0;
+ *ps = s;
+ return 0;
+}
+
(DIR) diff --git a/src/libventi/version.c b/src/libventi/version.c
t@@ -0,0 +1,115 @@
+#include <u.h>
+#include <libc.h>
+#include <venti.h>
+
+static char *okvers[] = {
+ "02",
+ nil,
+};
+
+/*
+static char EBigString[] = "string too long";
+static char EBigPacket[] = "packet too long";
+static char ENullString[] = "missing string";
+*/
+static char EBadVersion[] = "bad format in version string";
+
+static int
+vtreadversion(VtConn *z, char *q, char *v, int nv)
+{
+ int n;
+
+ for(;;){
+ if(nv <= 1){
+ werrstr("version too long");
+ return -1;
+ }
+ n = read(z->infd, v, 1);
+ if(n <= 0){
+ if(n == 0)
+ werrstr("unexpected eof");
+ return -1;
+ }
+ if(*v == '\n'){
+ *v = 0;
+ break;
+ }
+ if((uchar)*v < ' ' || (uchar)*v > 0x7f || (*q && *v != *q)){
+ werrstr(EBadVersion);
+ return -1;
+ }
+ v++;
+ nv--;
+ if(*q)
+ q++;
+ }
+ return 0;
+}
+
+int
+vtversion(VtConn *z)
+{
+ char buf[VtMaxStringSize], *p, *ep, *prefix, *pp;
+ int i;
+
+ qlock(&z->lk);
+ if(z->state != VtStateAlloc){
+ werrstr("bad session state");
+ qunlock(&z->lk);
+ return -1;
+ }
+
+ qlock(&z->inlk);
+ qlock(&z->outlk);
+
+ p = buf;
+ ep = buf + sizeof buf;
+ prefix = "venti-";
+ p = seprint(p, ep, "%s", prefix);
+ p += strlen(p);
+ for(i=0; okvers[i]; i++)
+ p = seprint(p, ep, "%s%s", i ? ":" : "", okvers[i]);
+ p = seprint(p, ep, "-libventi\n");
+ assert(p-buf < sizeof buf);
+
+ if(write(z->outfd, buf, p-buf) != p-buf)
+ goto Err;
+ vtdebug(z, "version string out: %s", buf);
+
+ if(vtreadversion(z, prefix, buf, sizeof buf) < 0)
+ goto Err;
+ vtdebug(z, "version string in: %s", buf);
+
+ p = buf+strlen(prefix);
+ for(;;){
+ pp = strpbrk(p, ":-");
+ for(i=0; okvers[i]; i++)
+ if(strlen(okvers[i]) == pp-p && memcmp(okvers[i], p, pp-p) == 0){
+ *pp = 0;
+ z->version = vtstrdup(p);
+ goto Okay;
+ }
+ }
+ werrstr("unable to negotiate version");
+ goto Err;
+
+Okay:
+ z->state = VtStateConnected;
+ qunlock(&z->inlk);
+ qunlock(&z->outlk);
+ qunlock(&z->lk);
+ return 0;
+
+Err:
+ if(z->infd >= 0)
+ close(z->infd);
+ if(z->outfd >= 0 && z->outfd != z->infd)
+ close(z->outfd);
+ z->infd = -1;
+ z->outfd = -1;
+ z->state = VtStateClosed;
+ qunlock(&z->inlk);
+ qunlock(&z->outlk);
+ qunlock(&z->lk);
+ return -1;
+}
(DIR) diff --git a/src/libventi/zero.c b/src/libventi/zero.c
t@@ -0,0 +1,55 @@
+#include <u.h>
+#include <libc.h>
+#include <venti.h>
+
+void
+vtzeroextend(int type, uchar *buf, uint n, uint nn)
+{
+ uchar *p, *ep;
+
+ switch(type&7) {
+ case 0:
+ memset(buf+n, 0, nn-n);
+ break;
+ default:
+ p = buf + (n/VtScoreSize)*VtScoreSize;
+ ep = buf + (nn/VtScoreSize)*VtScoreSize;
+ while(p < ep) {
+ memmove(p, vtzeroscore, VtScoreSize);
+ p += VtScoreSize;
+ }
+ memset(p, 0, buf+nn-p);
+ break;
+ }
+}
+
+uint
+vtzerotruncate(int type, uchar *buf, uint n)
+{
+ uchar *p;
+
+ if(type == VtRootType){
+ if(n < VtRootSize)
+ return n;
+ return VtRootSize;
+ }
+
+ switch(type&7){
+ case 0:
+ for(p = buf + n; p > buf; p--) {
+ if(p[-1] != 0)
+ break;
+ }
+ return p - buf;
+ default:
+ /* ignore slop at end of block */
+ p = buf + (n/VtScoreSize)*VtScoreSize;
+
+ while(p > buf) {
+ if(memcmp(p - VtScoreSize, vtzeroscore, VtScoreSize) != 0)
+ break;
+ p -= VtScoreSize;
+ }
+ return p - buf;
+ }
+}
(DIR) diff --git a/src/libventi/zeroscore.c b/src/libventi/zeroscore.c
t@@ -0,0 +1,10 @@
+#include <u.h>
+#include <libc.h>
+#include <venti.h>
+
+/* score of a zero length block */
+uchar vtzeroscore[VtScoreSize] = {
+ 0xda, 0x39, 0xa3, 0xee, 0x5e, 0x6b, 0x4b, 0x0d, 0x32, 0x55,
+ 0xbf, 0xef, 0x95, 0x60, 0x18, 0x90, 0xaf, 0xd8, 0x07, 0x09
+};
+