diff options
| -rw-r--r-- | diff-tree-helper.c | 6 | ||||
| -rw-r--r-- | diff.c | 67 | ||||
| -rw-r--r-- | diff.h | 13 |
3 files changed, 62 insertions, 24 deletions
diff --git a/diff-tree-helper.c b/diff-tree-helper.c index 621f90ad09..a68328321a 100644 --- a/diff-tree-helper.c +++ b/diff-tree-helper.c @@ -35,7 +35,7 @@ static int parse_oneside_change(const char *cp, struct diff_spec *one, if (strncmp(cp, "\tblob\t", 6)) return -1; cp += 6; - if (get_sha1_hex(cp, one->u.sha1)) + if (get_sha1_hex(cp, one->blob_sha1)) return -1; cp += 40; if (*cp++ != '\t') @@ -83,13 +83,13 @@ static int parse_diff_tree_output(const char *buf, if (strncmp(cp, "\tblob\t", 6)) return -1; cp += 6; - if (get_sha1_hex(cp, old.u.sha1)) + if (get_sha1_hex(cp, old.blob_sha1)) return -1; cp += 40; if (strncmp(cp, "->", 2)) return -1; cp += 2; - if (get_sha1_hex(cp, new.u.sha1)) + if (get_sha1_hex(cp, new.blob_sha1)) return -1; cp += 40; if (*cp++ != '\t') @@ -132,11 +132,50 @@ static void builtin_diff(const char *name, execlp("/bin/sh","sh", "-c", cmd, NULL); } +/* + * Given a name and sha1 pair, if the dircache tells us the file in + * the work tree has that object contents, return true, so that + * prepare_temp_file() does not have to inflate and extract. + */ +static int work_tree_matches(const char *name, const unsigned char *sha1) +{ + struct cache_entry *ce; + struct stat st; + int pos, len; + + /* We do not read the cache ourselves here, because the + * benchmark with my previous version that always reads cache + * shows that it makes things worse for diff-tree comparing + * two linux-2.6 kernel trees in an already checked out work + * tree. This is because most diff-tree comparison deals with + * only a small number of files, while reading the cache is + * expensive for a large project, and its cost outweighs the + * savings we get by not inflating the object to a temporary + * file. Practically, this code only helps when we are used + * by diff-cache --cached, which does read the cache before + * calling us. + */ + if (!active_cache) + return 0; + + len = strlen(name); + pos = cache_name_pos(name, len); + if (pos < 0) + return 0; + ce = active_cache[pos]; + if ((stat(name, &st) < 0) || + cache_match_stat(ce, &st) || + memcmp(sha1, ce->sha1, 20)) + return 0; + return 1; +} + static void prepare_temp_file(const char *name, struct diff_tempfile *temp, struct diff_spec *one) { static unsigned char null_sha1[20] = { 0, }; + int use_work_tree = 0; if (!one->file_valid) { not_a_valid_file: @@ -150,20 +189,22 @@ static void prepare_temp_file(const char *name, } if (one->sha1_valid && - !memcmp(one->u.sha1, null_sha1, sizeof(null_sha1))) { - one->sha1_valid = 0; - one->u.name = name; - } + (!memcmp(one->blob_sha1, null_sha1, sizeof(null_sha1)) || + work_tree_matches(name, one->blob_sha1))) + use_work_tree = 1; - if (!one->sha1_valid) { + if (!one->sha1_valid || use_work_tree) { struct stat st; - temp->name = one->u.name; + temp->name = name; if (stat(temp->name, &st) < 0) { if (errno == ENOENT) goto not_a_valid_file; die("stat(%s): %s", temp->name, strerror(errno)); } - strcpy(temp->hex, sha1_to_hex(null_sha1)); + if (!one->sha1_valid) + strcpy(temp->hex, sha1_to_hex(null_sha1)); + else + strcpy(temp->hex, sha1_to_hex(one->blob_sha1)); sprintf(temp->mode, "%06o", S_IFREG |ce_permissions(st.st_mode)); } @@ -173,10 +214,10 @@ static void prepare_temp_file(const char *name, char type[20]; unsigned long size; - blob = read_sha1_file(one->u.sha1, type, &size); + blob = read_sha1_file(one->blob_sha1, type, &size); if (!blob || strcmp(type, "blob")) die("unable to read blob object for %s (%s)", - name, sha1_to_hex(one->u.sha1)); + name, sha1_to_hex(one->blob_sha1)); strcpy(temp->tmp_path, ".diff_XXXXXX"); fd = mkstemp(temp->tmp_path); @@ -187,7 +228,7 @@ static void prepare_temp_file(const char *name, close(fd); free(blob); temp->name = temp->tmp_path; - strcpy(temp->hex, sha1_to_hex(one->u.sha1)); + strcpy(temp->hex, sha1_to_hex(one->blob_sha1)); temp->hex[40] = 0; sprintf(temp->mode, "%06o", one->mode); } @@ -286,7 +327,7 @@ void diff_addremove(int addremove, unsigned mode, char concatpath[PATH_MAX]; struct diff_spec spec[2], *one, *two; - memcpy(spec[0].u.sha1, sha1, 20); + memcpy(spec[0].blob_sha1, sha1, 20); spec[0].mode = mode; spec[0].sha1_valid = spec[0].file_valid = 1; spec[1].file_valid = 0; @@ -311,9 +352,9 @@ void diff_change(unsigned old_mode, unsigned new_mode, char concatpath[PATH_MAX]; struct diff_spec spec[2]; - memcpy(spec[0].u.sha1, old_sha1, 20); + memcpy(spec[0].blob_sha1, old_sha1, 20); spec[0].mode = old_mode; - memcpy(spec[1].u.sha1, new_sha1, 20); + memcpy(spec[1].blob_sha1, new_sha1, 20); spec[1].mode = new_mode; spec[0].sha1_valid = spec[0].file_valid = 1; spec[1].sha1_valid = spec[1].file_valid = 1; @@ -20,15 +20,12 @@ extern void diff_unmerge(const char *path); /* These are for diff-tree-helper */ struct diff_spec { - union { - const char *name; /* path on the filesystem */ - unsigned char sha1[20]; /* blob object ID */ - } u; + unsigned char blob_sha1[20]; unsigned short mode; /* file mode */ - unsigned sha1_valid : 1; /* if true, use u.sha1 and trust mode. - * (however with a NULL SHA1, read them - * from the file!). - * if false, use u.name and read mode from + unsigned sha1_valid : 1; /* if true, use blob_sha1 and trust mode; + * however with a NULL SHA1, read them + * from the file system. + * if false, use the name and read mode from * the filesystem. */ unsigned file_valid : 1; /* if false the file does not even exist */ |