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#include "cache.h"
#include "tree-walk.h"
#include "tree.h"
void init_tree_desc(struct tree_desc *desc, const void *buffer, unsigned long size)
{
desc->buffer = buffer;
desc->size = size;
}
void *fill_tree_descriptor(struct tree_desc *desc, const unsigned char *sha1)
{
unsigned long size = 0;
void *buf = NULL;
if (sha1) {
buf = read_object_with_reference(sha1, tree_type, &size, NULL);
if (!buf)
die("unable to read tree %s", sha1_to_hex(sha1));
}
init_tree_desc(desc, buf, size);
return buf;
}
static int entry_compare(struct name_entry *a, struct name_entry *b)
{
return base_name_compare(
a->path, tree_entry_len(a->path, a->sha1), a->mode,
b->path, tree_entry_len(b->path, b->sha1), b->mode);
}
static void entry_clear(struct name_entry *a)
{
memset(a, 0, sizeof(*a));
}
static void entry_extract(struct tree_desc *t, struct name_entry *a)
{
a->sha1 = tree_entry_extract(t, &a->path, &a->mode);
}
void update_tree_entry(struct tree_desc *desc)
{
const void *buf = desc->buffer;
unsigned long size = desc->size;
int len = strlen(buf) + 1 + 20;
if (size < len)
die("corrupt tree file");
desc->buffer = (char *) buf + len;
desc->size = size - len;
}
static const char *get_mode(const char *str, unsigned int *modep)
{
unsigned char c;
unsigned int mode = 0;
while ((c = *str++) != ' ') {
if (c < '0' || c > '7')
return NULL;
mode = (mode << 3) + (c - '0');
}
*modep = mode;
return str;
}
const unsigned char *tree_entry_extract(struct tree_desc *desc, const char **pathp, unsigned int *modep)
{
const void *tree = desc->buffer;
unsigned long size = desc->size;
int len = strlen(tree)+1;
const unsigned char *sha1 = (unsigned char *) tree + len;
const char *path;
unsigned int mode;
path = get_mode(tree, &mode);
if (!path || size < len + 20)
die("corrupt tree file");
*pathp = path;
*modep = canon_mode(mode);
return sha1;
}
int tree_entry(struct tree_desc *desc, struct name_entry *entry)
{
const void *tree = desc->buffer;
const char *path;
unsigned long len, size = desc->size;
if (!size)
return 0;
path = get_mode(tree, &entry->mode);
if (!path)
die("corrupt tree file");
entry->path = path;
len = strlen(path);
path += len + 1;
entry->sha1 = (const unsigned char *) path;
path += 20;
len = path - (char *) tree;
if (len > size)
die("corrupt tree file");
desc->buffer = path;
desc->size = size - len;
return 1;
}
void traverse_trees(int n, struct tree_desc *t, const char *base, traverse_callback_t callback)
{
struct name_entry *entry = xmalloc(n*sizeof(*entry));
for (;;) {
unsigned long mask = 0;
int i, last;
last = -1;
for (i = 0; i < n; i++) {
if (!t[i].size)
continue;
entry_extract(t+i, entry+i);
if (last >= 0) {
int cmp = entry_compare(entry+i, entry+last);
/*
* Is the new name bigger than the old one?
* Ignore it
*/
if (cmp > 0)
continue;
/*
* Is the new name smaller than the old one?
* Ignore all old ones
*/
if (cmp < 0)
mask = 0;
}
mask |= 1ul << i;
last = i;
}
if (!mask)
break;
/*
* Update the tree entries we've walked, and clear
* all the unused name-entries.
*/
for (i = 0; i < n; i++) {
if (mask & (1ul << i)) {
update_tree_entry(t+i);
continue;
}
entry_clear(entry + i);
}
callback(n, mask, entry, base);
}
free(entry);
}
static int find_tree_entry(struct tree_desc *t, const char *name, unsigned char *result, unsigned *mode)
{
int namelen = strlen(name);
while (t->size) {
const char *entry;
const unsigned char *sha1;
int entrylen, cmp;
sha1 = tree_entry_extract(t, &entry, mode);
update_tree_entry(t);
entrylen = tree_entry_len(entry, sha1);
if (entrylen > namelen)
continue;
cmp = memcmp(name, entry, entrylen);
if (cmp > 0)
continue;
if (cmp < 0)
break;
if (entrylen == namelen) {
hashcpy(result, sha1);
return 0;
}
if (name[entrylen] != '/')
continue;
if (!S_ISDIR(*mode))
break;
if (++entrylen == namelen) {
hashcpy(result, sha1);
return 0;
}
return get_tree_entry(sha1, name + entrylen, result, mode);
}
return -1;
}
int get_tree_entry(const unsigned char *tree_sha1, const char *name, unsigned char *sha1, unsigned *mode)
{
int retval;
void *tree;
unsigned long size;
struct tree_desc t;
unsigned char root[20];
tree = read_object_with_reference(tree_sha1, tree_type, &size, root);
if (!tree)
return -1;
if (name[0] == '\0') {
hashcpy(sha1, root);
return 0;
}
init_tree_desc(&t, tree, size);
retval = find_tree_entry(&t, name, sha1, mode);
free(tree);
return retval;
}
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