git/cache-tree.c
Shawn Pearce e702496e43 Convert memcpy(a,b,20) to hashcpy(a,b).
This abstracts away the size of the hash values when copying them
from memory location to memory location, much as the introduction
of hashcmp abstracted away hash value comparsion.

A few call sites were using char* rather than unsigned char* so
I added the cast rather than open hashcpy to be void*.  This is a
reasonable tradeoff as most call sites already use unsigned char*
and the existing hashcmp is also declared to be unsigned char*.

[jc: Splitted the patch to "master" part, to be followed by a
 patch for merge-recursive.c which is not in "master" yet.

 Fixed the cast in the latter hunk to combine-diff.c which was
 wrong in the original.

 Also converted ones left-over in combine-diff.c, diff-lib.c and
 upload-pack.c ]

Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-08-23 13:53:10 -07:00

558 lines
12 KiB
C

#include "cache.h"
#include "tree.h"
#include "cache-tree.h"
#define DEBUG 0
struct cache_tree *cache_tree(void)
{
struct cache_tree *it = xcalloc(1, sizeof(struct cache_tree));
it->entry_count = -1;
return it;
}
void cache_tree_free(struct cache_tree **it_p)
{
int i;
struct cache_tree *it = *it_p;
if (!it)
return;
for (i = 0; i < it->subtree_nr; i++)
if (it->down[i])
cache_tree_free(&it->down[i]->cache_tree);
free(it->down);
free(it);
*it_p = NULL;
}
static int subtree_name_cmp(const char *one, int onelen,
const char *two, int twolen)
{
if (onelen < twolen)
return -1;
if (twolen < onelen)
return 1;
return memcmp(one, two, onelen);
}
static int subtree_pos(struct cache_tree *it, const char *path, int pathlen)
{
struct cache_tree_sub **down = it->down;
int lo, hi;
lo = 0;
hi = it->subtree_nr;
while (lo < hi) {
int mi = (lo + hi) / 2;
struct cache_tree_sub *mdl = down[mi];
int cmp = subtree_name_cmp(path, pathlen,
mdl->name, mdl->namelen);
if (!cmp)
return mi;
if (cmp < 0)
hi = mi;
else
lo = mi + 1;
}
return -lo-1;
}
static struct cache_tree_sub *find_subtree(struct cache_tree *it,
const char *path,
int pathlen,
int create)
{
struct cache_tree_sub *down;
int pos = subtree_pos(it, path, pathlen);
if (0 <= pos)
return it->down[pos];
if (!create)
return NULL;
pos = -pos-1;
if (it->subtree_alloc <= it->subtree_nr) {
it->subtree_alloc = alloc_nr(it->subtree_alloc);
it->down = xrealloc(it->down, it->subtree_alloc *
sizeof(*it->down));
}
it->subtree_nr++;
down = xmalloc(sizeof(*down) + pathlen + 1);
down->cache_tree = NULL;
down->namelen = pathlen;
memcpy(down->name, path, pathlen);
down->name[pathlen] = 0;
if (pos < it->subtree_nr)
memmove(it->down + pos + 1,
it->down + pos,
sizeof(down) * (it->subtree_nr - pos - 1));
it->down[pos] = down;
return down;
}
struct cache_tree_sub *cache_tree_sub(struct cache_tree *it, const char *path)
{
int pathlen = strlen(path);
return find_subtree(it, path, pathlen, 1);
}
void cache_tree_invalidate_path(struct cache_tree *it, const char *path)
{
/* a/b/c
* ==> invalidate self
* ==> find "a", have it invalidate "b/c"
* a
* ==> invalidate self
* ==> if "a" exists as a subtree, remove it.
*/
const char *slash;
int namelen;
struct cache_tree_sub *down;
#if DEBUG
fprintf(stderr, "cache-tree invalidate <%s>\n", path);
#endif
if (!it)
return;
slash = strchr(path, '/');
it->entry_count = -1;
if (!slash) {
int pos;
namelen = strlen(path);
pos = subtree_pos(it, path, namelen);
if (0 <= pos) {
cache_tree_free(&it->down[pos]->cache_tree);
free(it->down[pos]);
/* 0 1 2 3 4 5
* ^ ^subtree_nr = 6
* pos
* move 4 and 5 up one place (2 entries)
* 2 = 6 - 3 - 1 = subtree_nr - pos - 1
*/
memmove(it->down+pos, it->down+pos+1,
sizeof(struct cache_tree_sub *) *
(it->subtree_nr - pos - 1));
it->subtree_nr--;
}
return;
}
namelen = slash - path;
down = find_subtree(it, path, namelen, 0);
if (down)
cache_tree_invalidate_path(down->cache_tree, slash + 1);
}
static int verify_cache(struct cache_entry **cache,
int entries)
{
int i, funny;
/* Verify that the tree is merged */
funny = 0;
for (i = 0; i < entries; i++) {
struct cache_entry *ce = cache[i];
if (ce_stage(ce)) {
if (10 < ++funny) {
fprintf(stderr, "...\n");
break;
}
fprintf(stderr, "%s: unmerged (%s)\n",
ce->name, sha1_to_hex(ce->sha1));
}
}
if (funny)
return -1;
/* Also verify that the cache does not have path and path/file
* at the same time. At this point we know the cache has only
* stage 0 entries.
*/
funny = 0;
for (i = 0; i < entries - 1; i++) {
/* path/file always comes after path because of the way
* the cache is sorted. Also path can appear only once,
* which means conflicting one would immediately follow.
*/
const char *this_name = cache[i]->name;
const char *next_name = cache[i+1]->name;
int this_len = strlen(this_name);
if (this_len < strlen(next_name) &&
strncmp(this_name, next_name, this_len) == 0 &&
next_name[this_len] == '/') {
if (10 < ++funny) {
fprintf(stderr, "...\n");
break;
}
fprintf(stderr, "You have both %s and %s\n",
this_name, next_name);
}
}
if (funny)
return -1;
return 0;
}
static void discard_unused_subtrees(struct cache_tree *it)
{
struct cache_tree_sub **down = it->down;
int nr = it->subtree_nr;
int dst, src;
for (dst = src = 0; src < nr; src++) {
struct cache_tree_sub *s = down[src];
if (s->used)
down[dst++] = s;
else {
cache_tree_free(&s->cache_tree);
free(s);
it->subtree_nr--;
}
}
}
int cache_tree_fully_valid(struct cache_tree *it)
{
int i;
if (!it)
return 0;
if (it->entry_count < 0 || !has_sha1_file(it->sha1))
return 0;
for (i = 0; i < it->subtree_nr; i++) {
if (!cache_tree_fully_valid(it->down[i]->cache_tree))
return 0;
}
return 1;
}
static int update_one(struct cache_tree *it,
struct cache_entry **cache,
int entries,
const char *base,
int baselen,
int missing_ok,
int dryrun)
{
unsigned long size, offset;
char *buffer;
int i;
if (0 <= it->entry_count && has_sha1_file(it->sha1))
return it->entry_count;
/*
* We first scan for subtrees and update them; we start by
* marking existing subtrees -- the ones that are unmarked
* should not be in the result.
*/
for (i = 0; i < it->subtree_nr; i++)
it->down[i]->used = 0;
/*
* Find the subtrees and update them.
*/
for (i = 0; i < entries; i++) {
struct cache_entry *ce = cache[i];
struct cache_tree_sub *sub;
const char *path, *slash;
int pathlen, sublen, subcnt;
path = ce->name;
pathlen = ce_namelen(ce);
if (pathlen <= baselen || memcmp(base, path, baselen))
break; /* at the end of this level */
slash = strchr(path + baselen, '/');
if (!slash)
continue;
/*
* a/bbb/c (base = a/, slash = /c)
* ==>
* path+baselen = bbb/c, sublen = 3
*/
sublen = slash - (path + baselen);
sub = find_subtree(it, path + baselen, sublen, 1);
if (!sub->cache_tree)
sub->cache_tree = cache_tree();
subcnt = update_one(sub->cache_tree,
cache + i, entries - i,
path,
baselen + sublen + 1,
missing_ok,
dryrun);
i += subcnt - 1;
sub->used = 1;
}
discard_unused_subtrees(it);
/*
* Then write out the tree object for this level.
*/
size = 8192;
buffer = xmalloc(size);
offset = 0;
for (i = 0; i < entries; i++) {
struct cache_entry *ce = cache[i];
struct cache_tree_sub *sub;
const char *path, *slash;
int pathlen, entlen;
const unsigned char *sha1;
unsigned mode;
path = ce->name;
pathlen = ce_namelen(ce);
if (pathlen <= baselen || memcmp(base, path, baselen))
break; /* at the end of this level */
slash = strchr(path + baselen, '/');
if (slash) {
entlen = slash - (path + baselen);
sub = find_subtree(it, path + baselen, entlen, 0);
if (!sub)
die("cache-tree.c: '%.*s' in '%s' not found",
entlen, path + baselen, path);
i += sub->cache_tree->entry_count - 1;
sha1 = sub->cache_tree->sha1;
mode = S_IFDIR;
}
else {
sha1 = ce->sha1;
mode = ntohl(ce->ce_mode);
entlen = pathlen - baselen;
}
if (!missing_ok && !has_sha1_file(sha1))
return error("invalid object %s", sha1_to_hex(sha1));
if (!ce->ce_mode)
continue; /* entry being removed */
if (size < offset + entlen + 100) {
size = alloc_nr(offset + entlen + 100);
buffer = xrealloc(buffer, size);
}
offset += sprintf(buffer + offset,
"%o %.*s", mode, entlen, path + baselen);
buffer[offset++] = 0;
hashcpy((unsigned char*)buffer + offset, sha1);
offset += 20;
#if DEBUG
fprintf(stderr, "cache-tree update-one %o %.*s\n",
mode, entlen, path + baselen);
#endif
}
if (dryrun) {
unsigned char hdr[200];
int hdrlen;
write_sha1_file_prepare(buffer, offset, tree_type, it->sha1,
hdr, &hdrlen);
}
else
write_sha1_file(buffer, offset, tree_type, it->sha1);
free(buffer);
it->entry_count = i;
#if DEBUG
fprintf(stderr, "cache-tree update-one (%d ent, %d subtree) %s\n",
it->entry_count, it->subtree_nr,
sha1_to_hex(it->sha1));
#endif
return i;
}
int cache_tree_update(struct cache_tree *it,
struct cache_entry **cache,
int entries,
int missing_ok,
int dryrun)
{
int i;
i = verify_cache(cache, entries);
if (i)
return i;
i = update_one(it, cache, entries, "", 0, missing_ok, dryrun);
if (i < 0)
return i;
return 0;
}
static void *write_one(struct cache_tree *it,
char *path,
int pathlen,
char *buffer,
unsigned long *size,
unsigned long *offset)
{
int i;
/* One "cache-tree" entry consists of the following:
* path (NUL terminated)
* entry_count, subtree_nr ("%d %d\n")
* tree-sha1 (missing if invalid)
* subtree_nr "cache-tree" entries for subtrees.
*/
if (*size < *offset + pathlen + 100) {
*size = alloc_nr(*offset + pathlen + 100);
buffer = xrealloc(buffer, *size);
}
*offset += sprintf(buffer + *offset, "%.*s%c%d %d\n",
pathlen, path, 0,
it->entry_count, it->subtree_nr);
#if DEBUG
if (0 <= it->entry_count)
fprintf(stderr, "cache-tree <%.*s> (%d ent, %d subtree) %s\n",
pathlen, path, it->entry_count, it->subtree_nr,
sha1_to_hex(it->sha1));
else
fprintf(stderr, "cache-tree <%.*s> (%d subtree) invalid\n",
pathlen, path, it->subtree_nr);
#endif
if (0 <= it->entry_count) {
hashcpy((unsigned char*)buffer + *offset, it->sha1);
*offset += 20;
}
for (i = 0; i < it->subtree_nr; i++) {
struct cache_tree_sub *down = it->down[i];
if (i) {
struct cache_tree_sub *prev = it->down[i-1];
if (subtree_name_cmp(down->name, down->namelen,
prev->name, prev->namelen) <= 0)
die("fatal - unsorted cache subtree");
}
buffer = write_one(down->cache_tree, down->name, down->namelen,
buffer, size, offset);
}
return buffer;
}
void *cache_tree_write(struct cache_tree *root, unsigned long *size_p)
{
char path[PATH_MAX];
unsigned long size = 8192;
char *buffer = xmalloc(size);
*size_p = 0;
path[0] = 0;
return write_one(root, path, 0, buffer, &size, size_p);
}
static struct cache_tree *read_one(const char **buffer, unsigned long *size_p)
{
const char *buf = *buffer;
unsigned long size = *size_p;
const char *cp;
char *ep;
struct cache_tree *it;
int i, subtree_nr;
it = NULL;
/* skip name, but make sure name exists */
while (size && *buf) {
size--;
buf++;
}
if (!size)
goto free_return;
buf++; size--;
it = cache_tree();
cp = buf;
it->entry_count = strtol(cp, &ep, 10);
if (cp == ep)
goto free_return;
cp = ep;
subtree_nr = strtol(cp, &ep, 10);
if (cp == ep)
goto free_return;
while (size && *buf && *buf != '\n') {
size--;
buf++;
}
if (!size)
goto free_return;
buf++; size--;
if (0 <= it->entry_count) {
if (size < 20)
goto free_return;
hashcpy(it->sha1, (unsigned char*)buf);
buf += 20;
size -= 20;
}
#if DEBUG
if (0 <= it->entry_count)
fprintf(stderr, "cache-tree <%s> (%d ent, %d subtree) %s\n",
*buffer, it->entry_count, subtree_nr,
sha1_to_hex(it->sha1));
else
fprintf(stderr, "cache-tree <%s> (%d subtrees) invalid\n",
*buffer, subtree_nr);
#endif
/*
* Just a heuristic -- we do not add directories that often but
* we do not want to have to extend it immediately when we do,
* hence +2.
*/
it->subtree_alloc = subtree_nr + 2;
it->down = xcalloc(it->subtree_alloc, sizeof(struct cache_tree_sub *));
for (i = 0; i < subtree_nr; i++) {
/* read each subtree */
struct cache_tree *sub;
struct cache_tree_sub *subtree;
const char *name = buf;
sub = read_one(&buf, &size);
if (!sub)
goto free_return;
subtree = cache_tree_sub(it, name);
subtree->cache_tree = sub;
}
if (subtree_nr != it->subtree_nr)
die("cache-tree: internal error");
*buffer = buf;
*size_p = size;
return it;
free_return:
cache_tree_free(&it);
return NULL;
}
struct cache_tree *cache_tree_read(const char *buffer, unsigned long size)
{
if (buffer[0])
return NULL; /* not the whole tree */
return read_one(&buffer, &size);
}
struct cache_tree *cache_tree_find(struct cache_tree *it, const char *path)
{
while (*path) {
const char *slash;
struct cache_tree_sub *sub;
slash = strchr(path, '/');
if (!slash)
slash = path + strlen(path);
/* between path and slash is the name of the
* subtree to look for.
*/
sub = find_subtree(it, path, slash - path, 0);
if (!sub)
return NULL;
it = sub->cache_tree;
if (slash)
while (*slash && *slash == '/')
slash++;
if (!slash || !*slash)
return it; /* prefix ended with slashes */
path = slash;
}
return it;
}