git/cache-tree.c at patch-1 · rtyley/git · GitHub

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#include "cache.h"

#include "lockfile.h"

#include "tree.h"

#include "tree-walk.h"

#include "cache-tree.h"

#ifndef DEBUG

#define DEBUG 0

#endif

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[i]);

}

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;

ALLOC_GROW(it->down, it->subtree_nr + 1, it->subtree_alloc);

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);

}

static int do_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 0;

slash = strchrnul(path, '/');

namelen = slash - path;

it->entry_count = -1;

if (!*slash) {

int pos;

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 1;

}

down = find_subtree(it, path, namelen, 0);

if (down)

do_invalidate_path(down->cache_tree, slash + 1);

return 1;

}

void cache_tree_invalidate_path(struct index_state *istate, const char *path)

{

if (do_invalidate_path(istate->cache_tree, path))

istate->cache_changed |= CACHE_TREE_CHANGED;

}

static int verify_cache(struct cache_entry **cache,

int entries, int flags)

{

int i, funny;

int silent = flags & WRITE_TREE_SILENT;

/* Verify that the tree is merged */

funny = 0;

for (i = 0; i < entries; i++) {

const struct cache_entry *ce = cache[i];

if (ce_stage(ce)) {

if (silent)

return -1;

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 *skip_count,

int flags)

{

struct strbuf buffer;

int missing_ok = flags & WRITE_TREE_MISSING_OK;

int dryrun = flags & WRITE_TREE_DRY_RUN;

int repair = flags & WRITE_TREE_REPAIR;

int to_invalidate = 0;

int i;

assert(!(dryrun && repair));

*skip_count = 0;

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.

i = 0;

while (i < entries) {

const struct cache_entry *ce = cache[i];

struct cache_tree_sub *sub;

const char *path, *slash;

int pathlen, sublen, subcnt, subskip;

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) {

i++;

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,

&subskip,

flags);

if (subcnt < 0)

return subcnt;

if (!subcnt)

die("index cache-tree records empty sub-tree");

i += subcnt;

sub->count = subcnt; /* to be used in the next loop */

*skip_count += subskip;

sub->used = 1;

}

discard_unused_subtrees(it);

* Then write out the tree object for this level.

strbuf_init(&buffer, 8192);

i = 0;

while (i < entries) {

const struct cache_entry *ce = cache[i];

struct cache_tree_sub *sub;

const char *path, *slash;

int pathlen, entlen;

const unsigned char *sha1;

unsigned mode;

int expected_missing = 0;

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->count;

sha1 = sub->cache_tree->sha1;

mode = S_IFDIR;

if (sub->cache_tree->entry_count < 0) {

to_invalidate = 1;

expected_missing = 1;

}

else {

sha1 = ce->sha1;

mode = ce->ce_mode;

entlen = pathlen - baselen;

i++;

}

if (mode != S_IFGITLINK && !missing_ok && !has_sha1_file(sha1)) {

strbuf_release(&buffer);

if (expected_missing)

return -1;

return error("invalid object %06o %s for '%.*s'",

mode, sha1_to_hex(sha1), entlen+baselen, path);

}

* CE_REMOVE entries are removed before the index is

* written to disk. Skip them to remain consistent

* with the future on-disk index.

if (ce->ce_flags & CE_REMOVE) {

*skip_count = *skip_count + 1;

continue;

}

* CE_INTENT_TO_ADD entries exist on on-disk index but

* they are not part of generated trees. Invalidate up

* to root to force cache-tree users to read elsewhere.

if (ce->ce_flags & CE_INTENT_TO_ADD) {

to_invalidate = 1;

continue;

}

strbuf_grow(&buffer, entlen + 100);

strbuf_addf(&buffer, "%o %.*s%c", mode, entlen, path + baselen, '\0');

strbuf_add(&buffer, sha1, 20);

#if DEBUG

fprintf(stderr, "cache-tree update-one %o %.*s\n",

mode, entlen, path + baselen);

#endif

}

if (repair) {

unsigned char sha1[20];

hash_sha1_file(buffer.buf, buffer.len, tree_type, sha1);

if (has_sha1_file(sha1))

hashcpy(it->sha1, sha1);

else

to_invalidate = 1;

} else if (dryrun)

hash_sha1_file(buffer.buf, buffer.len, tree_type, it->sha1);

else if (write_sha1_file(buffer.buf, buffer.len, tree_type, it->sha1)) {

strbuf_release(&buffer);

return -1;

}

strbuf_release(&buffer);

it->entry_count = to_invalidate ? -1 : i - *skip_count;

#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 index_state *istate, int flags)

{

struct cache_tree *it = istate->cache_tree;

struct cache_entry **cache = istate->cache;

int entries = istate->cache_nr;

int skip, i = verify_cache(cache, entries, flags);

if (i)

return i;

i = update_one(it, cache, entries, "", 0, &skip, flags);

if (i < 0)

return i;

istate->cache_changed |= CACHE_TREE_CHANGED;

return 0;

}

static void write_one(struct strbuf *buffer, struct cache_tree *it,

const char *path, int pathlen)

{

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.

strbuf_grow(buffer, pathlen + 100);

strbuf_add(buffer, path, pathlen);

strbuf_addf(buffer, "%c%d %d\n", 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) {

strbuf_add(buffer, it->sha1, 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");

}

write_one(buffer, down->cache_tree, down->name, down->namelen);

}

void cache_tree_write(struct strbuf *sb, struct cache_tree *root)

{

write_one(sb, root, "", 0);

}

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, (const 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);

}

static struct cache_tree *cache_tree_find(struct cache_tree *it, const char *path)

{

if (!it)

return NULL;

while (*path) {

const char *slash;

struct cache_tree_sub *sub;

slash = strchrnul(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;

path = slash;

while (*path == '/')

path++;

}

return it;

}

int write_cache_as_tree(unsigned char *sha1, int flags, const char *prefix)

{

int entries, was_valid, newfd;

struct lock_file *lock_file;

* We can't free this memory, it becomes part of a linked list

* parsed atexit()

lock_file = xcalloc(1, sizeof(struct lock_file));

newfd = hold_locked_index(lock_file, 1);

entries = read_cache();

if (entries < 0)

return WRITE_TREE_UNREADABLE_INDEX;

if (flags & WRITE_TREE_IGNORE_CACHE_TREE)

cache_tree_free(&(active_cache_tree));

if (!active_cache_tree)

active_cache_tree = cache_tree();

was_valid = cache_tree_fully_valid(active_cache_tree);

if (!was_valid) {

if (cache_tree_update(&the_index, flags) < 0)

return WRITE_TREE_UNMERGED_INDEX;

if (0 <= newfd) {

if (!write_locked_index(&the_index, lock_file, COMMIT_LOCK))

newfd = -1;

}

/* Not being able to write is fine -- we are only interested

* in updating the cache-tree part, and if the next caller

* ends up using the old index with unupdated cache-tree part

* it misses the work we did here, but that is just a

* performance penalty and not a big deal.

}

if (prefix) {

struct cache_tree *subtree =

cache_tree_find(active_cache_tree, prefix);

if (!subtree)

return WRITE_TREE_PREFIX_ERROR;

hashcpy(sha1, subtree->sha1);

}

else

hashcpy(sha1, active_cache_tree->sha1);

if (0 <= newfd)

rollback_lock_file(lock_file);

return 0;

}

static void prime_cache_tree_rec(struct cache_tree *it, struct tree *tree)

{

struct tree_desc desc;

struct name_entry entry;

int cnt;

hashcpy(it->sha1, tree->object.sha1);

init_tree_desc(&desc, tree->buffer, tree->size);

cnt = 0;

while (tree_entry(&desc, &entry)) {

if (!S_ISDIR(entry.mode))

cnt++;

else {

struct cache_tree_sub *sub;

struct tree *subtree = lookup_tree(entry.sha1);

if (!subtree->object.parsed)

parse_tree(subtree);

sub = cache_tree_sub(it, entry.path);

sub->cache_tree = cache_tree();

prime_cache_tree_rec(sub->cache_tree, subtree);

cnt += sub->cache_tree->entry_count;

}

it->entry_count = cnt;

}

void prime_cache_tree(struct index_state *istate, struct tree *tree)

{

cache_tree_free(&istate->cache_tree);

istate->cache_tree = cache_tree();

prime_cache_tree_rec(istate->cache_tree, tree);

istate->cache_changed |= CACHE_TREE_CHANGED;

}

* find the cache_tree that corresponds to the current level without

* exploding the full path into textual form. The root of the

* cache tree is given as "root", and our current level is "info".

* (1) When at root level, info->prev is NULL, so it is "root" itself.

* (2) Otherwise, find the cache_tree that corresponds to one level

* above us, and find ourselves in there.

static struct cache_tree *find_cache_tree_from_traversal(struct cache_tree *root,

struct traverse_info *info)

{

struct cache_tree *our_parent;

if (!info->prev)

return root;

our_parent = find_cache_tree_from_traversal(root, info->prev);

return cache_tree_find(our_parent, info->name.path);

}

int cache_tree_matches_traversal(struct cache_tree *root,

struct name_entry *ent,

struct traverse_info *info)

{

struct cache_tree *it;

it = find_cache_tree_from_traversal(root, info);

it = cache_tree_find(it, ent->path);

if (it && it->entry_count > 0 && !hashcmp(ent->sha1, it->sha1))

return it->entry_count;

return 0;

}

int update_main_cache_tree(int flags)

{

if (!the_index.cache_tree)

the_index.cache_tree = cache_tree();

return cache_tree_update(&the_index, flags);

}

git/cache-tree.c at patch-1 · rtyley/git · GitHub

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