Merge branch 'mk/diff'

diff --git a/tree-walk.c b/tree-walk.c
index bf8bfdfdf8564d10b0ca5450dc62612e0ae4525d..cbb24eb3f663cd0370f528d983a2266a55b91c4f 100644 (file)
--- a/tree-walk.c
+++ b/tree-walk.c
@@ -2,6 +2,44 @@
 #include "tree-walk.h"
 #include "tree.h"
 
+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;
+}
+
+static void decode_tree_entry(struct tree_desc *desc, const void *buf, unsigned long size)
+{
+       const char *path;
+       unsigned int mode, len;
+
+       path = get_mode(buf, &mode);
+       if (!path)
+               die("corrupt tree file");
+       len = strlen(path) + 1;
+
+       /* Initialize the descriptor entry */
+       desc->entry.path = path;
+       desc->entry.mode = mode;
+       desc->entry.sha1 = (const unsigned char *)(path + len);
+}
+
+void init_tree_desc(struct tree_desc *desc, const void *buffer, unsigned long size)
+{
+       desc->buffer = buffer;
+       desc->size = size;
+       if (size)
+               decode_tree_entry(desc, buffer, size);
+}
+
 void *fill_tree_descriptor(struct tree_desc *desc, const unsigned char *sha1)
 {
        unsigned long size = 0;
@@ -12,16 +50,15 @@ void *fill_tree_descriptor(struct tree_desc *desc, const unsigned char *sha1)
                if (!buf)
                        die("unable to read tree %s", sha1_to_hex(sha1));
        }
-       desc->size = size;
-       desc->buf = buf;
+       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, a->pathlen, a->mode,
-                       b->path, b->pathlen, b->mode);
+                       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)
@@ -31,36 +68,34 @@ static void entry_clear(struct name_entry *a)
 
 static void entry_extract(struct tree_desc *t, struct name_entry *a)
 {
-       a->sha1 = tree_entry_extract(t, &a->path, &a->mode);
-       a->pathlen = strlen(a->path);
+       *a = t->entry;
 }
 
 void update_tree_entry(struct tree_desc *desc)
 {
-       void *buf = desc->buf;
+       const void *buf = desc->buffer;
+       const unsigned char *end = desc->entry.sha1 + 20;
        unsigned long size = desc->size;
-       int len = strlen(buf) + 1 + 20;
+       unsigned long len = end - (const unsigned char *)buf;
 
        if (size < len)
                die("corrupt tree file");
-       desc->buf = buf + len;
-       desc->size = size - len;
+       buf = end;
+       size -= len;
+       desc->buffer = buf;
+       desc->size = size;
+       if (size)
+               decode_tree_entry(desc, buf, size);
 }
 
-const unsigned char *tree_entry_extract(struct tree_desc *desc, const char **pathp, unsigned int *modep)
+int tree_entry(struct tree_desc *desc, struct name_entry *entry)
 {
-       void *tree = desc->buf;
-       unsigned long size = desc->size;
-       int len = strlen(tree)+1;
-       const unsigned char *sha1 = tree + len;
-       const char *path = strchr(tree, ' ');
-       unsigned int mode;
+       if (!desc->size)
+               return 0;
 
-       if (!path || size < len + 20 || sscanf(tree, "%o", &mode) != 1)
-               die("corrupt tree file");
-       *pathp = path+1;
-       *modep = canon_mode(mode);
-       return sha1;
+       *entry = desc->entry;
+       update_tree_entry(desc);
+       return 1;
 }
 
 void traverse_trees(int n, struct tree_desc *t, const char *base, traverse_callback_t callback)
@@ -68,7 +103,6 @@ void traverse_trees(int n, struct tree_desc *t, const char *base, traverse_callb
        struct name_entry *entry = xmalloc(n*sizeof(*entry));
 
        for (;;) {
-               struct name_entry entry[3];
                unsigned long mask = 0;
                int i, last;
 
@@ -115,3 +149,61 @@ void traverse_trees(int n, struct tree_desc *t, const char *base, traverse_callb
        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;
+}
+