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authorNguyễn Thái Ngọc Duy <pclouds@gmail.com>2010-12-15 15:02:42 (GMT)
committerJunio C Hamano <gitster@pobox.com>2011-02-03 22:08:16 (GMT)
commit48932677d62e426b3f26ac236384cb5195fb9dfd (patch)
treed58115641e35cc305af9b5f48e6fcf39f5cfee35 /tree-diff.c
parent3bd2bcfa982c69c0f5722c3dfe72b15cd0469d15 (diff)
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diff-tree: convert base+baselen to writable strbuf
In traversing trees, a full path is splitted into two parts: base directory and entry. They are however quite often concatenated whenever a full path is needed. Current code allocates a new buffer, do two memcpy(), use it, then release. Instead this patch turns "base" to a writable, extendable buffer. When a concatenation is needed, the callee only needs to append "entry" to base, use it, then truncate the entry out again. "base" must remain unchanged before and after entering a function. This avoids quite a bit of malloc() and memcpy(). Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Diffstat (limited to 'tree-diff.c')
-rw-r--r--tree-diff.c120
1 files changed, 52 insertions, 68 deletions
diff --git a/tree-diff.c b/tree-diff.c
index 23f4478..45a3845 100644
--- a/tree-diff.c
+++ b/tree-diff.c
@@ -6,34 +6,18 @@
#include "diffcore.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, struct strbuf *base);
-static char *malloc_fullname(const char *base, int baselen, const char *path, int pathlen)
-{
- char *fullname = xmalloc(baselen + pathlen + 1);
- memcpy(fullname, base, baselen);
- memcpy(fullname + baselen, path, pathlen);
- fullname[baselen + pathlen] = 0;
- return fullname;
-}
-
-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)
+static int compare_tree_entry(struct tree_desc *t1, struct tree_desc *t2,
+ struct strbuf *base, struct diff_options *opt)
{
unsigned mode1, mode2;
const char *path1, *path2;
const unsigned char *sha1, *sha2;
int cmp, pathlen1, pathlen2;
- char *fullname;
+ int old_baselen = base->len;
+ int retval = 0;
sha1 = tree_entry_extract(t1, &path1, &mode1);
sha2 = tree_entry_extract(t2, &path2, &mode2);
@@ -42,11 +26,11 @@ static int compare_tree_entry(struct tree_desc *t1, struct tree_desc *t2, const
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);
+ show_entry(opt, "-", t1, base);
return -1;
}
if (cmp > 0) {
- show_entry(opt, "+", t2, base, baselen);
+ show_entry(opt, "+", t2, base);
return 1;
}
if (!DIFF_OPT_TST(opt, FIND_COPIES_HARDER) && !hashcmp(sha1, sha2) && mode1 == mode2)
@@ -57,33 +41,29 @@ static int compare_tree_entry(struct tree_desc *t1, struct tree_desc *t2, const
* 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);
+ show_entry(opt, "-", t1, base);
+ show_entry(opt, "+", t2, base);
return 0;
}
+ strbuf_add(base, path1, pathlen1);
if (DIFF_OPT_TST(opt, RECURSIVE) && S_ISDIR(mode1)) {
- int retval;
- char *newbase = malloc_base(base, baselen, path1, pathlen1);
if (DIFF_OPT_TST(opt, TREE_IN_RECURSIVE)) {
- newbase[baselen + pathlen1] = 0;
opt->change(opt, mode1, mode2,
- sha1, sha2, newbase, 0, 0);
- newbase[baselen + pathlen1] = '/';
+ sha1, sha2, base->buf, 0, 0);
}
- retval = diff_tree_sha1(sha1, sha2, newbase, opt);
- free(newbase);
- return retval;
+ strbuf_addch(base, '/');
+ retval = diff_tree_sha1(sha1, sha2, base->buf, opt);
+ } else {
+ opt->change(opt, mode1, mode2, sha1, sha2, base->buf, 0, 0);
}
-
- fullname = malloc_fullname(base, baselen, path1, pathlen1);
- opt->change(opt, mode1, mode2, sha1, sha2, fullname, 0, 0);
- free(fullname);
+ strbuf_setlen(base, old_baselen);
return 0;
}
/* 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)
+static void show_tree(struct diff_options *opt, const char *prefix,
+ struct tree_desc *desc, struct strbuf *base)
{
int all_interesting = 0;
while (desc->size) {
@@ -92,30 +72,32 @@ static void show_tree(struct diff_options *opt, const char *prefix, struct tree_
if (all_interesting)
show = 1;
else {
- show = tree_entry_interesting(&desc->entry, base, baselen, &opt->pathspec);
+ show = tree_entry_interesting(&desc->entry, base,
+ &opt->pathspec);
if (show == 2)
all_interesting = 1;
}
if (show < 0)
break;
if (show)
- show_entry(opt, prefix, desc, base, baselen);
+ show_entry(opt, prefix, desc, base);
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)
+static void show_entry(struct diff_options *opt, const char *prefix,
+ struct tree_desc *desc, struct strbuf *base)
{
unsigned mode;
const char *path;
const unsigned char *sha1 = tree_entry_extract(desc, &path, &mode);
int pathlen = tree_entry_len(path, sha1);
+ int old_baselen = base->len;
+ strbuf_add(base, path, pathlen);
if (DIFF_OPT_TST(opt, RECURSIVE) && S_ISDIR(mode)) {
enum object_type type;
- char *newbase = malloc_base(base, baselen, path, pathlen);
struct tree_desc inner;
void *tree;
unsigned long size;
@@ -124,28 +106,25 @@ static void show_entry(struct diff_options *opt, const char *prefix, struct tree
if (!tree || type != OBJ_TREE)
die("corrupt tree sha %s", sha1_to_hex(sha1));
- if (DIFF_OPT_TST(opt, TREE_IN_RECURSIVE)) {
- newbase[baselen + pathlen] = 0;
- opt->add_remove(opt, *prefix, mode, sha1, newbase, 0);
- newbase[baselen + pathlen] = '/';
- }
+ if (DIFF_OPT_TST(opt, TREE_IN_RECURSIVE))
+ opt->add_remove(opt, *prefix, mode, sha1, base->buf, 0);
- init_tree_desc(&inner, tree, size);
- show_tree(opt, prefix, &inner, newbase, baselen + 1 + pathlen);
+ strbuf_addch(base, '/');
+ init_tree_desc(&inner, tree, size);
+ show_tree(opt, prefix, &inner, base);
free(tree);
- free(newbase);
- } else {
- char *fullname = malloc_fullname(base, baselen, path, pathlen);
- opt->add_remove(opt, prefix[0], mode, sha1, fullname, 0);
- free(fullname);
- }
+ } else
+ opt->add_remove(opt, prefix[0], mode, sha1, base->buf, 0);
+
+ strbuf_setlen(base, old_baselen);
}
-static void skip_uninteresting(struct tree_desc *t, const char *base, int baselen, struct diff_options *opt, int *all_interesting)
+static void skip_uninteresting(struct tree_desc *t, struct strbuf *base,
+ struct diff_options *opt, int *all_interesting)
{
while (t->size) {
- int show = tree_entry_interesting(&t->entry, base, baselen, &opt->pathspec);
+ int show = tree_entry_interesting(&t->entry, base, &opt->pathspec);
if (show == 2)
*all_interesting = 1;
if (!show) {
@@ -159,37 +138,40 @@ static void skip_uninteresting(struct tree_desc *t, const char *base, int basele
}
}
-int diff_tree(struct tree_desc *t1, struct tree_desc *t2, const char *base, struct diff_options *opt)
+int diff_tree(struct tree_desc *t1, struct tree_desc *t2,
+ const char *base_str, struct diff_options *opt)
{
- int baselen = strlen(base);
+ struct strbuf base;
+ int baselen = strlen(base_str);
int all_t1_interesting = 0;
int all_t2_interesting = 0;
+ strbuf_init(&base, PATH_MAX);
+ strbuf_add(&base, base_str, baselen);
+
for (;;) {
if (DIFF_OPT_TST(opt, QUICK) &&
DIFF_OPT_TST(opt, HAS_CHANGES))
break;
if (opt->pathspec.nr) {
if (!all_t1_interesting)
- skip_uninteresting(t1, base, baselen, opt,
- &all_t1_interesting);
+ skip_uninteresting(t1, &base, opt, &all_t1_interesting);
if (!all_t2_interesting)
- skip_uninteresting(t2, base, baselen, opt,
- &all_t2_interesting);
+ skip_uninteresting(t2, &base, opt, &all_t2_interesting);
}
if (!t1->size) {
if (!t2->size)
break;
- show_entry(opt, "+", t2, base, baselen);
+ show_entry(opt, "+", t2, &base);
update_tree_entry(t2);
continue;
}
if (!t2->size) {
- show_entry(opt, "-", t1, base, baselen);
+ show_entry(opt, "-", t1, &base);
update_tree_entry(t1);
continue;
}
- switch (compare_tree_entry(t1, t2, base, baselen, opt)) {
+ switch (compare_tree_entry(t1, t2, &base, opt)) {
case -1:
update_tree_entry(t1);
continue;
@@ -202,6 +184,8 @@ int diff_tree(struct tree_desc *t1, struct tree_desc *t2, const char *base, stru
}
die("git diff-tree: internal error");
}
+
+ strbuf_release(&base);
return 0;
}