diff options
Diffstat (limited to 'tree-diff.c')
| -rw-r--r-- | tree-diff.c | 296 |
1 files changed, 296 insertions, 0 deletions
diff --git a/tree-diff.c b/tree-diff.c new file mode 100644 index 0000000000..b2f35dc3d8 --- /dev/null +++ b/tree-diff.c @@ -0,0 +1,296 @@ +/* + * Helper functions for tree diff generation + */ +#include "cache.h" +#include "diff.h" +#include "tree.h" + +static char *malloc_base(const char *base, int baselen, const char *path, int pathlen) +{ + char *newbase = xmalloc(baselen + pathlen + 2); + memcpy(newbase, base, baselen); + memcpy(newbase + baselen, path, pathlen); + memcpy(newbase + baselen + pathlen, "/", 2); + return newbase; +} + +static void show_entry(struct diff_options *opt, const char *prefix, struct tree_desc *desc, + const char *base, int baselen); + +static int compare_tree_entry(struct tree_desc *t1, struct tree_desc *t2, const char *base, int baselen, struct diff_options *opt) +{ + unsigned mode1, mode2; + const char *path1, *path2; + const unsigned char *sha1, *sha2; + int cmp, pathlen1, pathlen2; + + sha1 = tree_entry_extract(t1, &path1, &mode1); + sha2 = tree_entry_extract(t2, &path2, &mode2); + + pathlen1 = tree_entry_len(path1, sha1); + pathlen2 = tree_entry_len(path2, sha2); + cmp = base_name_compare(path1, pathlen1, mode1, path2, pathlen2, mode2); + if (cmp < 0) { + show_entry(opt, "-", t1, base, baselen); + return -1; + } + if (cmp > 0) { + show_entry(opt, "+", t2, base, baselen); + return 1; + } + if (!opt->find_copies_harder && !hashcmp(sha1, sha2) && mode1 == mode2) + return 0; + + /* + * If the filemode has changed to/from a directory from/to a regular + * file, we need to consider it a remove and an add. + */ + if (S_ISDIR(mode1) != S_ISDIR(mode2)) { + show_entry(opt, "-", t1, base, baselen); + show_entry(opt, "+", t2, base, baselen); + return 0; + } + + if (opt->recursive && S_ISDIR(mode1)) { + int retval; + char *newbase = malloc_base(base, baselen, path1, pathlen1); + if (opt->tree_in_recursive) + opt->change(opt, mode1, mode2, + sha1, sha2, base, path1); + retval = diff_tree_sha1(sha1, sha2, newbase, opt); + free(newbase); + return retval; + } + + opt->change(opt, mode1, mode2, sha1, sha2, base, path1); + return 0; +} + +/* + * Is a tree entry interesting given the pathspec we have? + * + * Return: + * - positive for yes + * - zero for no + * - negative for "no, and no subsequent entries will be either" + */ +static int tree_entry_interesting(struct tree_desc *desc, const char *base, int baselen, struct diff_options *opt) +{ + const char *path; + const unsigned char *sha1; + unsigned mode; + int i; + int pathlen; + + if (!opt->nr_paths) + return 1; + + sha1 = tree_entry_extract(desc, &path, &mode); + + pathlen = tree_entry_len(path, sha1); + + for (i=0; i < opt->nr_paths; i++) { + const char *match = opt->paths[i]; + int matchlen = opt->pathlens[i]; + + if (baselen >= matchlen) { + /* If it doesn't match, move along... */ + if (strncmp(base, match, matchlen)) + continue; + + /* The base is a subdirectory of a path which was specified. */ + return 1; + } + + /* Does the base match? */ + if (strncmp(base, match, baselen)) + continue; + + match += baselen; + matchlen -= baselen; + + if (pathlen > matchlen) + continue; + + if (matchlen > pathlen) { + if (match[pathlen] != '/') + continue; + if (!S_ISDIR(mode)) + continue; + } + + if (strncmp(path, match, pathlen)) + continue; + + return 1; + } + return 0; /* No matches */ +} + +/* A whole sub-tree went away or appeared */ +static void show_tree(struct diff_options *opt, const char *prefix, struct tree_desc *desc, const char *base, int baselen) +{ + while (desc->size) { + int show = tree_entry_interesting(desc, base, baselen, opt); + if (show < 0) + break; + if (show) + show_entry(opt, prefix, desc, base, baselen); + update_tree_entry(desc); + } +} + +/* A file entry went away or appeared */ +static void show_entry(struct diff_options *opt, const char *prefix, struct tree_desc *desc, + const char *base, int baselen) +{ + unsigned mode; + const char *path; + const unsigned char *sha1 = tree_entry_extract(desc, &path, &mode); + + if (opt->recursive && S_ISDIR(mode)) { + enum object_type type; + int pathlen = tree_entry_len(path, sha1); + char *newbase = malloc_base(base, baselen, path, pathlen); + struct tree_desc inner; + void *tree; + + tree = read_sha1_file(sha1, &type, &inner.size); + if (!tree || type != OBJ_TREE) + die("corrupt tree sha %s", sha1_to_hex(sha1)); + + inner.buf = tree; + show_tree(opt, prefix, &inner, newbase, baselen + 1 + pathlen); + + free(tree); + free(newbase); + } else { + opt->add_remove(opt, prefix[0], mode, sha1, base, path); + } +} + +static void skip_uninteresting(struct tree_desc *t, const char *base, int baselen, struct diff_options *opt) +{ + while (t->size) { + int show = tree_entry_interesting(t, base, baselen, opt); + if (!show) { + update_tree_entry(t); + continue; + } + /* Skip it all? */ + if (show < 0) + t->size = 0; + return; + } +} + +int diff_tree(struct tree_desc *t1, struct tree_desc *t2, const char *base, struct diff_options *opt) +{ + int baselen = strlen(base); + + for (;;) { + if (opt->quiet && opt->has_changes) + break; + if (opt->nr_paths) { + skip_uninteresting(t1, base, baselen, opt); + skip_uninteresting(t2, base, baselen, opt); + } + if (!t1->size) { + if (!t2->size) + break; + show_entry(opt, "+", t2, base, baselen); + update_tree_entry(t2); + continue; + } + if (!t2->size) { + show_entry(opt, "-", t1, base, baselen); + update_tree_entry(t1); + continue; + } + switch (compare_tree_entry(t1, t2, base, baselen, opt)) { + case -1: + update_tree_entry(t1); + continue; + case 0: + update_tree_entry(t1); + /* Fallthrough */ + case 1: + update_tree_entry(t2); + continue; + } + die("git-diff-tree: internal error"); + } + return 0; +} + +int diff_tree_sha1(const unsigned char *old, const unsigned char *new, const char *base, struct diff_options *opt) +{ + void *tree1, *tree2; + struct tree_desc t1, t2; + int retval; + + tree1 = read_object_with_reference(old, tree_type, &t1.size, NULL); + if (!tree1) + die("unable to read source tree (%s)", sha1_to_hex(old)); + tree2 = read_object_with_reference(new, tree_type, &t2.size, NULL); + if (!tree2) + die("unable to read destination tree (%s)", sha1_to_hex(new)); + t1.buf = tree1; + t2.buf = tree2; + retval = diff_tree(&t1, &t2, base, opt); + free(tree1); + free(tree2); + return retval; +} + +int diff_root_tree_sha1(const unsigned char *new, const char *base, struct diff_options *opt) +{ + int retval; + void *tree; + struct tree_desc empty, real; + + tree = read_object_with_reference(new, tree_type, &real.size, NULL); + if (!tree) + die("unable to read root tree (%s)", sha1_to_hex(new)); + real.buf = tree; + + empty.size = 0; + empty.buf = ""; + retval = diff_tree(&empty, &real, base, opt); + free(tree); + return retval; +} + +static int count_paths(const char **paths) +{ + int i = 0; + while (*paths++) + i++; + return i; +} + +void diff_tree_release_paths(struct diff_options *opt) +{ + free(opt->pathlens); +} + +void diff_tree_setup_paths(const char **p, struct diff_options *opt) +{ + opt->nr_paths = 0; + opt->pathlens = NULL; + opt->paths = NULL; + + if (p) { + int i; + + opt->paths = p; + opt->nr_paths = count_paths(p); + if (opt->nr_paths == 0) { + opt->pathlens = NULL; + return; + } + opt->pathlens = xmalloc(opt->nr_paths * sizeof(int)); + for (i=0; i < opt->nr_paths; i++) + opt->pathlens[i] = strlen(p[i]); + } +} |