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![Linus Torvalds](/assets/img/avatar_default.png)
This removes slightly more lines than it adds, but the real reason for doing this is that future optimizations will require more setup of the tree descriptor, and so we want to do it in one place. Also renamed the "desc.buf" field to "desc.buffer" just to trigger compiler errors for old-style manual initializations, making sure I didn't miss anything. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Junio C Hamano <junkio@cox.net>
223 lines
4.5 KiB
C
223 lines
4.5 KiB
C
#include "cache.h"
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#include "tree-walk.h"
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#include "tree.h"
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void init_tree_desc(struct tree_desc *desc, const void *buffer, unsigned long size)
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{
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desc->buffer = buffer;
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desc->size = size;
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}
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void *fill_tree_descriptor(struct tree_desc *desc, const unsigned char *sha1)
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{
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unsigned long size = 0;
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void *buf = NULL;
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if (sha1) {
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buf = read_object_with_reference(sha1, tree_type, &size, NULL);
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if (!buf)
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die("unable to read tree %s", sha1_to_hex(sha1));
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}
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init_tree_desc(desc, buf, size);
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return buf;
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}
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static int entry_compare(struct name_entry *a, struct name_entry *b)
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{
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return base_name_compare(
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a->path, tree_entry_len(a->path, a->sha1), a->mode,
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b->path, tree_entry_len(b->path, b->sha1), b->mode);
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}
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static void entry_clear(struct name_entry *a)
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{
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memset(a, 0, sizeof(*a));
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}
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static void entry_extract(struct tree_desc *t, struct name_entry *a)
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{
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a->sha1 = tree_entry_extract(t, &a->path, &a->mode);
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}
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void update_tree_entry(struct tree_desc *desc)
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{
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const void *buf = desc->buffer;
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unsigned long size = desc->size;
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int len = strlen(buf) + 1 + 20;
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if (size < len)
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die("corrupt tree file");
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desc->buffer = (char *) buf + len;
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desc->size = size - len;
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}
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static const char *get_mode(const char *str, unsigned int *modep)
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{
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unsigned char c;
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unsigned int mode = 0;
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while ((c = *str++) != ' ') {
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if (c < '0' || c > '7')
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return NULL;
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mode = (mode << 3) + (c - '0');
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}
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*modep = mode;
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return str;
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}
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const unsigned char *tree_entry_extract(struct tree_desc *desc, const char **pathp, unsigned int *modep)
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{
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const void *tree = desc->buffer;
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unsigned long size = desc->size;
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int len = strlen(tree)+1;
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const unsigned char *sha1 = (unsigned char *) tree + len;
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const char *path;
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unsigned int mode;
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path = get_mode(tree, &mode);
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if (!path || size < len + 20)
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die("corrupt tree file");
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*pathp = path;
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*modep = canon_mode(mode);
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return sha1;
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}
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int tree_entry(struct tree_desc *desc, struct name_entry *entry)
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{
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const void *tree = desc->buffer;
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const char *path;
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unsigned long len, size = desc->size;
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if (!size)
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return 0;
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path = get_mode(tree, &entry->mode);
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if (!path)
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die("corrupt tree file");
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entry->path = path;
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len = strlen(path);
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path += len + 1;
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entry->sha1 = (const unsigned char *) path;
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path += 20;
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len = path - (char *) tree;
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if (len > size)
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die("corrupt tree file");
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desc->buffer = path;
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desc->size = size - len;
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return 1;
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}
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void traverse_trees(int n, struct tree_desc *t, const char *base, traverse_callback_t callback)
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{
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struct name_entry *entry = xmalloc(n*sizeof(*entry));
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for (;;) {
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unsigned long mask = 0;
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int i, last;
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last = -1;
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for (i = 0; i < n; i++) {
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if (!t[i].size)
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continue;
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entry_extract(t+i, entry+i);
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if (last >= 0) {
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int cmp = entry_compare(entry+i, entry+last);
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/*
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* Is the new name bigger than the old one?
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* Ignore it
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*/
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if (cmp > 0)
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continue;
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/*
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* Is the new name smaller than the old one?
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* Ignore all old ones
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*/
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if (cmp < 0)
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mask = 0;
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}
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mask |= 1ul << i;
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last = i;
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}
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if (!mask)
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break;
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/*
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* Update the tree entries we've walked, and clear
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* all the unused name-entries.
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*/
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for (i = 0; i < n; i++) {
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if (mask & (1ul << i)) {
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update_tree_entry(t+i);
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continue;
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}
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entry_clear(entry + i);
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}
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callback(n, mask, entry, base);
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}
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free(entry);
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}
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static int find_tree_entry(struct tree_desc *t, const char *name, unsigned char *result, unsigned *mode)
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{
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int namelen = strlen(name);
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while (t->size) {
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const char *entry;
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const unsigned char *sha1;
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int entrylen, cmp;
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sha1 = tree_entry_extract(t, &entry, mode);
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update_tree_entry(t);
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entrylen = tree_entry_len(entry, sha1);
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if (entrylen > namelen)
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continue;
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cmp = memcmp(name, entry, entrylen);
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if (cmp > 0)
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continue;
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if (cmp < 0)
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break;
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if (entrylen == namelen) {
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hashcpy(result, sha1);
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return 0;
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}
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if (name[entrylen] != '/')
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continue;
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if (!S_ISDIR(*mode))
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break;
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if (++entrylen == namelen) {
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hashcpy(result, sha1);
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return 0;
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}
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return get_tree_entry(sha1, name + entrylen, result, mode);
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}
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return -1;
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}
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int get_tree_entry(const unsigned char *tree_sha1, const char *name, unsigned char *sha1, unsigned *mode)
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{
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int retval;
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void *tree;
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unsigned long size;
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struct tree_desc t;
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unsigned char root[20];
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tree = read_object_with_reference(tree_sha1, tree_type, &size, root);
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if (!tree)
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return -1;
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if (name[0] == '\0') {
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hashcpy(sha1, root);
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return 0;
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}
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init_tree_desc(&t, tree, size);
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retval = find_tree_entry(&t, name, sha1, mode);
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free(tree);
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return retval;
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}
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