[PATCH 2/3] Rename git-diff-tree-helper to git-diff-helper.
[gitweb.git] / diff-tree.c
index 207617c8fa247821474948cde4e34aefe4d6b5f2..51e3274f36dd7792fdbd20fdde4f4e7546f3b10b 100644 (file)
@@ -1,8 +1,23 @@
+#include <ctype.h>
 #include "cache.h"
+#include "diff.h"
 
+static int silent = 0;
+static int verbose_header = 0;
+static int ignore_merges = 1;
 static int recursive = 0;
+static int read_stdin = 0;
+static int line_termination = '\n';
+static int generate_patch = 0;
+static const char *header = NULL;
+static const char *header_prefix = "";
 
-static int diff_tree_sha1(const unsigned char *old, const unsigned char *new, const char *src, const char *dst);
+// What paths are we interested in?
+static int nr_paths = 0;
+static char **paths = NULL;
+static int *pathlens = NULL;
+
+static int diff_tree_sha1(const unsigned char *old, const unsigned char *new, const char *base);
 
 static void update_tree_entry(void **bufp, unsigned long *sizep)
 {
@@ -11,7 +26,7 @@ static void update_tree_entry(void **bufp, unsigned long *sizep)
        int len = strlen(buf) + 1 + 20;
 
        if (size < len)
-               usage("corrupt tree file");
+               die("corrupt tree file");
        *bufp = buf + len;
        *sizep = size - len;
 }
@@ -23,25 +38,82 @@ static const unsigned char *extract(void *tree, unsigned long size, const char *
        const char *path = strchr(tree, ' ');
 
        if (!path || size < len + 20 || sscanf(tree, "%o", modep) != 1)
-               usage("corrupt tree file");
+               die("corrupt tree file");
        *pathp = path+1;
        return sha1;
 }
 
+static char *malloc_base(const char *base, const char *path, int pathlen)
+{
+       int baselen = strlen(base);
+       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_file(const char *prefix, void *tree, unsigned long size, const char *base);
+
+/* A whole sub-tree went away or appeared */
+static void show_tree(const char *prefix, void *tree, unsigned long size, const char *base)
+{
+       while (size) {
+               show_file(prefix, tree, size, base);
+               update_tree_entry(&tree, &size);
+       }
+}
+
+/* A file entry went away or appeared */
 static void show_file(const char *prefix, void *tree, unsigned long size, const char *base)
 {
        unsigned mode;
        const char *path;
        const unsigned char *sha1 = extract(tree, size, &path, &mode);
-       printf("%s%o %s %s%s%c", prefix, mode, sha1_to_hex(sha1), base, path, 0);
+
+       if (header) {
+               printf("%s", header);
+               header = NULL;
+       }
+
+       if (silent)
+               return;
+
+       if (recursive && S_ISDIR(mode)) {
+               char type[20];
+               unsigned long size;
+               char *newbase = malloc_base(base, path, strlen(path));
+               void *tree;
+
+               tree = read_sha1_file(sha1, type, &size);
+               if (!tree || strcmp(type, "tree"))
+                       die("corrupt tree sha %s", sha1_to_hex(sha1));
+
+               show_tree(prefix, tree, size, newbase);
+               
+               free(tree);
+               free(newbase);
+               return;
+       }
+
+       if (generate_patch) {
+               if (!S_ISDIR(mode))
+                       diff_addremove(prefix[0], mode, sha1, base, path);
+       }
+       else
+               printf("%s%06o\t%s\t%s\t%s%s%c", prefix, mode,
+                      S_ISDIR(mode) ? "tree" : "blob",
+                      sha1_to_hex(sha1), base, path,
+                      line_termination);
 }
 
-static int compare_tree_entry(void *tree1, unsigned long size1, void *tree2, unsigned long size2, const char *src, const char *dst)
+static int compare_tree_entry(void *tree1, unsigned long size1, void *tree2, unsigned long size2, const char *base)
 {
        unsigned mode1, mode2;
        const char *path1, *path2;
        const unsigned char *sha1, *sha2;
        int cmp, pathlen1, pathlen2;
+       char old_sha1_hex[50];
 
        sha1 = extract(tree1, size1, &path1, &mode1);
        sha2 = extract(tree2, size2, &path2, &mode2);
@@ -50,48 +122,123 @@ static int compare_tree_entry(void *tree1, unsigned long size1, void *tree2, uns
        pathlen2 = strlen(path2);
        cmp = cache_name_compare(path1, pathlen1, path2, pathlen2);
        if (cmp < 0) {
-               show_file("-", tree1, size1, src);
+               show_file("-", tree1, size1, base);
                return -1;
        }
        if (cmp > 0) {
-               show_file("+", tree2, size2, dst);
+               show_file("+", tree2, size2, base);
                return 1;
        }
        if (!memcmp(sha1, sha2, 20) && mode1 == mode2)
                return 0;
-       if (recursive && S_ISDIR(mode1) && S_ISDIR(mode2)) {
-               int srclen = strlen(src);
-               int dstlen = strlen(dst);
-               char *srcbase = malloc(srclen + pathlen1 + 2);
-               char *dstbase = malloc(srclen + pathlen1 + 2);
-               memcpy(srcbase, src, srclen);
-               memcpy(srcbase + srclen, path1, pathlen1);
-               memcpy(srcbase + srclen + pathlen1, "/", 2);
-               memcpy(dstbase, dst, dstlen);
-               memcpy(dstbase + dstlen, path2, pathlen2);
-               memcpy(dstbase + dstlen + pathlen2, "/", 2);
-               return diff_tree_sha1(sha1, sha2, srcbase, dstbase);
-       }
-
-       show_file("<", tree1, size1, src);
-       show_file(">", tree2, size2, dst);
+
+       /*
+        * 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_file("-", tree1, size1, base);
+               show_file("+", tree2, size2, base);
+               return 0;
+       }
+
+       if (recursive && S_ISDIR(mode1)) {
+               int retval;
+               char *newbase = malloc_base(base, path1, pathlen1);
+               retval = diff_tree_sha1(sha1, sha2, newbase);
+               free(newbase);
+               return retval;
+       }
+
+       if (header) {
+               printf("%s", header);
+               header = NULL;
+       }
+       if (silent)
+               return 0;
+
+       if (generate_patch) {
+               if (!S_ISDIR(mode1))
+                       diff_change(mode1, mode2, sha1, sha2, base, path1);
+       }
+       else {
+               strcpy(old_sha1_hex, sha1_to_hex(sha1));
+               printf("*%06o->%06o\t%s\t%s->%s\t%s%s%c", mode1, mode2,
+                      S_ISDIR(mode1) ? "tree" : "blob",
+                      old_sha1_hex, sha1_to_hex(sha2), base, path1,
+                      line_termination);
+       }
        return 0;
 }
 
-static int diff_tree(void *tree1, unsigned long size1, void *tree2, unsigned long size2, const char *src, const char *dst)
+static int interesting(void *tree, unsigned long size, const char *base)
+{
+       const char *path;
+       unsigned mode;
+       int i;
+       int baselen, pathlen;
+
+       if (!nr_paths)
+               return 1;
+
+       (void)extract(tree, size, &path, &mode);
+
+       pathlen = strlen(path);
+       baselen = strlen(base);
+
+       for (i=0; i < nr_paths; i++) {
+               const char *match = paths[i];
+               int matchlen = 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 (strncmp(path, match, pathlen))
+                       continue;
+
+               return 1;
+       }
+       return 0; /* No matches */
+}
+
+static int diff_tree(void *tree1, unsigned long size1, void *tree2, unsigned long size2, const char *base)
 {
        while (size1 | size2) {
+               if (nr_paths && size1 && !interesting(tree1, size1, base)) {
+                       update_tree_entry(&tree1, &size1);
+                       continue;
+               }
+               if (nr_paths && size2 && !interesting(tree2, size2, base)) {
+                       update_tree_entry(&tree2, &size2);
+                       continue;
+               }
                if (!size1) {
-                       show_file("+", tree2, size2, dst);
+                       show_file("+", tree2, size2, base);
                        update_tree_entry(&tree2, &size2);
                        continue;
                }
                if (!size2) {
-                       show_file("-", tree1, size1, src);
+                       show_file("-", tree1, size1, base);
                        update_tree_entry(&tree1, &size1);
                        continue;
                }
-               switch (compare_tree_entry(tree1, size1, tree2, size2, src, dst)) {
+               switch (compare_tree_entry(tree1, size1, tree2, size2, base)) {
                case -1:
                        update_tree_entry(&tree1, &size1);
                        continue;
@@ -102,46 +249,219 @@ static int diff_tree(void *tree1, unsigned long size1, void *tree2, unsigned lon
                        update_tree_entry(&tree2, &size2);
                        continue;
                }
-               usage("diff-tree: internal error");
+               die("diff-tree: internal error");
        }
        return 0;
 }
 
-static int diff_tree_sha1(const unsigned char *old, const unsigned char *new, const char *src, const char *dst)
+static int diff_tree_sha1(const unsigned char *old, const unsigned char *new, const char *base)
 {
        void *tree1, *tree2;
        unsigned long size1, size2;
-       char type[20];
        int retval;
 
-       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");
-       retval = diff_tree(tree1, size1, tree2, size2, src, dst);
+       tree1 = read_object_with_reference(old, "tree", &size1, 0);
+       if (!tree1)
+               die("unable to read source tree (%s)", sha1_to_hex(old));
+       tree2 = read_object_with_reference(new, "tree", &size2, 0);
+       if (!tree2)
+               die("unable to read destination tree (%s)", sha1_to_hex(new));
+       retval = diff_tree(tree1, size1, tree2, size2, base);
        free(tree1);
        free(tree2);
        return retval;
 }
 
+static int get_one_line(const char *msg, unsigned long len)
+{
+       int ret = 0;
+
+       while (len--) {
+               ret++;
+               if (*msg++ == '\n')
+                       break;
+       }
+       return ret;
+}
+
+static int add_author_info(char *buf, const char *line, int len)
+{
+       char *date;
+       unsigned int namelen;
+       unsigned long time;
+       int tz;
+
+       line += strlen("author ");
+       date = strchr(line, '>');
+       if (!date)
+               return 0;
+       namelen = ++date - line;
+       time = strtoul(date, &date, 10);
+       tz = strtol(date, NULL, 10);
+
+       return sprintf(buf, "Author: %.*s\nDate:   %s\n",
+               namelen, line,
+               show_date(time, tz));
+}
+
+static char *generate_header(const char *commit, const char *parent, const char *msg, unsigned long len)
+{
+       static char this_header[1000];
+       int offset;
+
+       offset = sprintf(this_header, "%s%s (from %s)\n", header_prefix, commit, parent);
+       if (verbose_header) {
+               int hdr = 1;
+
+               for (;;) {
+                       const char *line = msg;
+                       int linelen = get_one_line(msg, len);
+
+                       if (!linelen)
+                               break;
+                       if (offset + linelen + 10 > sizeof(this_header))
+                               break;
+
+                       msg += linelen;
+                       len -= linelen;
+                       if (linelen == 1)
+                               hdr = 0;
+                       if (hdr) {
+                               if (!memcmp(line, "author ", 7))
+                                       offset += add_author_info(this_header + offset, line, linelen);
+                               continue;
+                       }
+                       memset(this_header + offset, ' ', 4);
+                       memcpy(this_header + offset + 4, line, linelen);
+                       offset += linelen + 4;
+               }
+               this_header[offset++] = '\n';
+               this_header[offset] = 0;
+       }
+
+       return this_header;
+}
+
+static int diff_tree_stdin(char *line)
+{
+       int len = strlen(line);
+       unsigned char commit[20], parent[20];
+       unsigned long size, offset;
+       static char this_header[1000];
+       char *buf;
+
+       if (!len || line[len-1] != '\n')
+               return -1;
+       line[len-1] = 0;
+       if (get_sha1_hex(line, commit))
+               return -1;
+       if (isspace(line[40]) && !get_sha1_hex(line+41, parent)) {
+               line[40] = 0;
+               line[81] = 0;
+               sprintf(this_header, "%s (from %s)\n", line, line+41);
+               header = this_header;
+               return diff_tree_sha1(parent, commit, "");
+       }
+       buf = read_object_with_reference(commit, "commit", &size, NULL);
+       if (!buf)
+               return -1;
+
+       /* More than one parent? */
+       if (ignore_merges) {
+               if (!memcmp(buf + 46 + 48, "parent ", 7))
+                       return 0;
+       }
+
+       line[40] = 0;
+       offset = 46;
+       while (offset + 48 < size && !memcmp(buf + offset, "parent ", 7)) {
+               if (get_sha1_hex(buf + offset + 7, parent))
+                       return -1;
+               header = generate_header(line, sha1_to_hex(parent), buf, size);
+               diff_tree_sha1(parent, commit, "");
+               if (!header && verbose_header)
+                       header_prefix = "\ndiff-tree ";
+               offset += 48;
+       }
+       return -1;
+}
+
+static char *diff_tree_usage =
+"diff-tree [-p] [-r] [-z] [--stdin] [-m] [-s] [-v] <tree sha1> <tree sha1>";
+
 int main(int argc, char **argv)
 {
+       char line[1000];
        unsigned char old[20], new[20];
 
-       while (argc > 3) {
-               char *arg = argv[1];
+       for (;;) {
+               char *arg;
+
                argv++;
                argc--;
-               if (!strcmp(arg, "-R")) {
+               arg = *argv;
+               if (!arg || *arg != '-')
+                       break;
+
+               if (!strcmp(arg, "-")) {
+                       argv++;
+                       argc--;
+                       break;
+               }
+               if (!strcmp(arg, "-r")) {
                        recursive = 1;
                        continue;
                }
-               usage("diff-tree [-R] <tree sha1> <tree sha1>");
+               if (!strcmp(arg, "-p")) {
+                       recursive = generate_patch = 1;
+                       continue;
+               }
+               if (!strcmp(arg, "-z")) {
+                       line_termination = '\0';
+                       continue;
+               }
+               if (!strcmp(arg, "-m")) {
+                       ignore_merges = 0;
+                       continue;
+               }
+               if (!strcmp(arg, "-s")) {
+                       silent = 1;
+                       continue;
+               }
+               if (!strcmp(arg, "-v")) {
+                       verbose_header = 1;
+                       header_prefix = "diff-tree ";
+                       continue;
+               }
+               if (!strcmp(arg, "--stdin")) {
+                       read_stdin = 1;
+                       continue;
+               }
+               usage(diff_tree_usage);
+       }
+
+       if (!read_stdin) {
+               if (argc < 2 || get_sha1(argv[0], old) || get_sha1(argv[1], new))
+                       usage(diff_tree_usage);
+               argv += 2;
+               argc -= 2;
+       }
+
+       if (argc > 0) {
+               int i;
+
+               paths = argv;
+               nr_paths = argc;
+               pathlens = xmalloc(nr_paths * sizeof(int));
+               for (i=0; i<nr_paths; i++)
+                       pathlens[i] = strlen(paths[i]);
        }
 
-       if (argc != 3 || get_sha1_hex(argv[1], old) || get_sha1_hex(argv[2], new))
-               usage("diff-tree <tree sha1> <tree sha1>");
-       return diff_tree_sha1(old, new, "", "");
+       if (!read_stdin)
+               return diff_tree_sha1(old, new, "");
+
+       while (fgets(line, sizeof(line), stdin))
+               diff_tree_stdin(line);
+
+       return 0;
 }