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Add "diff-tree" program to show which files have changed between two …
…trees. Very useful for creating diffs efficiently, and in general to see what has changed in the namespace.
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Linus Torvalds
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Apr 9, 2005
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79517a0
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Original file line number | Diff line number | Diff line change |
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@@ -0,0 +1,109 @@ | ||
#include "cache.h" | ||
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struct tree_entry; | ||
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static struct tree_entry *update_tree_entry(void **bufp, unsigned long *sizep) | ||
{ | ||
void *buf = *bufp; | ||
unsigned long size = *sizep; | ||
int len = strlen(buf) + 1 + 20; | ||
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if (size < len) | ||
usage("corrupt tree file"); | ||
*bufp = buf + len; | ||
*sizep = size - len; | ||
return buf; | ||
} | ||
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static const unsigned char *extract(void *tree, unsigned long size, const char **pathp, unsigned int *modep) | ||
{ | ||
int len = strlen(tree)+1; | ||
const unsigned char *sha1 = tree + len; | ||
const char *path = strchr(tree, ' '); | ||
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if (!path || size < len + 20 || sscanf(tree, "%o", modep) != 1) | ||
usage("corrupt tree file"); | ||
*pathp = path+1; | ||
return sha1; | ||
} | ||
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static void show_file(const char *prefix, void *tree, unsigned long size) | ||
{ | ||
unsigned mode; | ||
const char *path; | ||
const unsigned char *sha1 = extract(tree, size, &path, &mode); | ||
printf("%s%o %s %s%c", prefix, mode, sha1_to_hex(sha1), path, 0); | ||
} | ||
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static int compare_tree_entry(void *tree1, unsigned long size1, void *tree2, unsigned long size2) | ||
{ | ||
unsigned mode1, mode2; | ||
const char *path1, *path2; | ||
const unsigned char *sha1, *sha2; | ||
int cmp; | ||
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sha1 = extract(tree1, size1, &path1, &mode1); | ||
sha2 = extract(tree2, size2, &path2, &mode2); | ||
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cmp = cache_name_compare(path1, strlen(path1), path2, strlen(path2)); | ||
if (cmp < 0) { | ||
show_file("-", tree1, size1); | ||
return -1; | ||
} | ||
if (cmp > 0) { | ||
show_file("+", tree2, size2); | ||
return 1; | ||
} | ||
if (!memcmp(sha1, sha2, 20) && mode1 == mode2) | ||
return 0; | ||
show_file("<", tree1, size1); | ||
show_file(">", tree2, size2); | ||
return 0; | ||
} | ||
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static int diff_tree(void *tree1, unsigned long size1, void *tree2, unsigned long size2) | ||
{ | ||
while (size1 | size2) { | ||
if (!size1) { | ||
show_file("+", tree2, size2); | ||
update_tree_entry(&tree2, &size2); | ||
continue; | ||
} | ||
if (!size2) { | ||
show_file("-", tree1, size1); | ||
update_tree_entry(&tree1, &size1); | ||
continue; | ||
} | ||
switch (compare_tree_entry(tree1, size1, tree2, size2)) { | ||
case -1: | ||
update_tree_entry(&tree1, &size1); | ||
continue; | ||
case 0: | ||
update_tree_entry(&tree1, &size1); | ||
/* Fallthrough */ | ||
case 1: | ||
update_tree_entry(&tree2, &size2); | ||
continue; | ||
} | ||
usage("diff-tree: internal error"); | ||
} | ||
return 0; | ||
} | ||
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int main(int argc, char **argv) | ||
{ | ||
unsigned char old[20], new[20]; | ||
void *tree1, *tree2; | ||
unsigned long size1, size2; | ||
char type[20]; | ||
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if (argc != 3 || get_sha1_hex(argv[1], old) || get_sha1_hex(argv[2], new)) | ||
usage("diff-tree <tree sha1> <tree sha1>"); | ||
tree1 = read_sha1_file(old, type, &size1); | ||
if (!tree1 || strcmp(type, "tree")) | ||
usage("unable to read source tree"); | ||
tree2 = read_sha1_file(new, type, &size2); | ||
if (!tree2 || strcmp(type, "tree")) | ||
usage("unable to read destination tree"); | ||
return diff_tree(tree1, size1, tree2, size2); | ||
} |