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>
Nguyễn Thái Ngọc Duy committed
Dec 15, 2010 at 22:02 UTC
48932677d62e426b3f26ac236384cb5195fb9dfd
3 files changed
+56
-71
tree-diff.c
+52
-68
@@ -6,34 +6,18 @@
6
#include "diffcore.h"
7
#include "tree.h"
8
9
-static char *malloc_base(const char *base, int baselen, const char *path, int pathlen)
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-{
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- char *newbase = xmalloc(baselen + pathlen + 2);
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- memcpy(newbase, base, baselen);
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- memcpy(newbase + baselen, path, pathlen);
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- memcpy(newbase + baselen + pathlen, "/", 2);
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- return newbase;
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-}
9
+static void show_entry(struct diff_options *opt, const char *prefix,
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+ struct tree_desc *desc, struct strbuf *base);
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18
-static char *malloc_fullname(const char *base, int baselen, const char *path, int pathlen)
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-{
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- char *fullname = xmalloc(baselen + pathlen + 1);
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- memcpy(fullname, base, baselen);
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- memcpy(fullname + baselen, path, pathlen);
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- fullname[baselen + pathlen] = 0;
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- return fullname;
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-}
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-
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-static void show_entry(struct diff_options *opt, const char *prefix, struct tree_desc *desc,
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- const char *base, int baselen);
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-
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-static int compare_tree_entry(struct tree_desc *t1, struct tree_desc *t2, const char *base, int baselen, struct diff_options *opt)
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+static int compare_tree_entry(struct tree_desc *t1, struct tree_desc *t2,
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+ struct strbuf *base, struct diff_options *opt)
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{
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unsigned mode1, mode2;
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const char *path1, *path2;
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const unsigned char *sha1, *sha2;
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int cmp, pathlen1, pathlen2;
36
- char *fullname;
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+ int old_baselen = base->len;
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+ int retval = 0;
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sha1 = tree_entry_extract(t1, &path1, &mode1);
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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
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pathlen2 = tree_entry_len(path2, sha2);
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cmp = base_name_compare(path1, pathlen1, mode1, path2, pathlen2, mode2);
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if (cmp < 0) {
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- show_entry(opt, "-", t1, base, baselen);
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+ show_entry(opt, "-", t1, base);
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return -1;
31
}
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if (cmp > 0) {
49
- show_entry(opt, "+", t2, base, baselen);
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+ show_entry(opt, "+", t2, base);
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return 1;
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}
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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
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* file, we need to consider it a remove and an add.
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*/
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if (S_ISDIR(mode1) != S_ISDIR(mode2)) {
60
- show_entry(opt, "-", t1, base, baselen);
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- show_entry(opt, "+", t2, base, baselen);
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+ show_entry(opt, "-", t1, base);
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+ show_entry(opt, "+", t2, base);
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return 0;
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}
48
49
+ strbuf_add(base, path1, pathlen1);
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if (DIFF_OPT_TST(opt, RECURSIVE) && S_ISDIR(mode1)) {
66
- int retval;
67
- char *newbase = malloc_base(base, baselen, path1, pathlen1);
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if (DIFF_OPT_TST(opt, TREE_IN_RECURSIVE)) {
69
- newbase[baselen + pathlen1] = 0;
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opt->change(opt, mode1, mode2,
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- sha1, sha2, newbase, 0, 0);
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- newbase[baselen + pathlen1] = '/';
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+ sha1, sha2, base->buf, 0, 0);
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}
74
- retval = diff_tree_sha1(sha1, sha2, newbase, opt);
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- free(newbase);
76
- return retval;
55
+ strbuf_addch(base, '/');
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+ retval = diff_tree_sha1(sha1, sha2, base->buf, opt);
57
+ } else {
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+ opt->change(opt, mode1, mode2, sha1, sha2, base->buf, 0, 0);
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}
78
-
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- fullname = malloc_fullname(base, baselen, path1, pathlen1);
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- opt->change(opt, mode1, mode2, sha1, sha2, fullname, 0, 0);
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- free(fullname);
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+ strbuf_setlen(base, old_baselen);
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return 0;
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}
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64
/* A whole sub-tree went away or appeared */
86
-static void show_tree(struct diff_options *opt, const char *prefix, struct tree_desc *desc, const char *base, int baselen)
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+static void show_tree(struct diff_options *opt, const char *prefix,
66
+ struct tree_desc *desc, struct strbuf *base)
67
{
68
int all_interesting = 0;
69
while (desc->size) {
@@ -92,30 +72,32 @@ static void show_tree(struct diff_options *opt, const char *prefix, struct tree_
72
if (all_interesting)
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show = 1;
74
else {
95
- show = tree_entry_interesting(&desc->entry, base, baselen, &opt->pathspec);
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+ show = tree_entry_interesting(&desc->entry, base,
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+ &opt->pathspec);
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if (show == 2)
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all_interesting = 1;
79
}
80
if (show < 0)
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break;
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if (show)
102
- show_entry(opt, prefix, desc, base, baselen);
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+ show_entry(opt, prefix, desc, base);
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update_tree_entry(desc);
85
}
86
}
87
88
/* A file entry went away or appeared */
108
-static void show_entry(struct diff_options *opt, const char *prefix, struct tree_desc *desc,
109
- const char *base, int baselen)
89
+static void show_entry(struct diff_options *opt, const char *prefix,
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+ struct tree_desc *desc, struct strbuf *base)
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{
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unsigned mode;
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const char *path;
94
const unsigned char *sha1 = tree_entry_extract(desc, &path, &mode);
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int pathlen = tree_entry_len(path, sha1);
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+ int old_baselen = base->len;
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98
+ strbuf_add(base, path, pathlen);
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if (DIFF_OPT_TST(opt, RECURSIVE) && S_ISDIR(mode)) {
100
enum object_type type;
118
- char *newbase = malloc_base(base, baselen, path, pathlen);
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struct tree_desc inner;
102
void *tree;
103
unsigned long size;
@@ -124,28 +106,25 @@ static void show_entry(struct diff_options *opt, const char *prefix, struct tree
106
if (!tree || type != OBJ_TREE)
107
die("corrupt tree sha %s", sha1_to_hex(sha1));
108
127
- if (DIFF_OPT_TST(opt, TREE_IN_RECURSIVE)) {
128
- newbase[baselen + pathlen] = 0;
129
- opt->add_remove(opt, *prefix, mode, sha1, newbase, 0);
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- newbase[baselen + pathlen] = '/';
131
- }
109
+ if (DIFF_OPT_TST(opt, TREE_IN_RECURSIVE))
110
+ opt->add_remove(opt, *prefix, mode, sha1, base->buf, 0);
111
133
- init_tree_desc(&inner, tree, size);
134
- show_tree(opt, prefix, &inner, newbase, baselen + 1 + pathlen);
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+ strbuf_addch(base, '/');
113
114
+ init_tree_desc(&inner, tree, size);
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+ show_tree(opt, prefix, &inner, base);
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free(tree);
137
- free(newbase);
138
- } else {
139
- char *fullname = malloc_fullname(base, baselen, path, pathlen);
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- opt->add_remove(opt, prefix[0], mode, sha1, fullname, 0);
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- free(fullname);
142
- }
117
+ } else
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+ opt->add_remove(opt, prefix[0], mode, sha1, base->buf, 0);
119
+
120
+ strbuf_setlen(base, old_baselen);
121
}
122
145
-static void skip_uninteresting(struct tree_desc *t, const char *base, int baselen, struct diff_options *opt, int *all_interesting)
123
+static void skip_uninteresting(struct tree_desc *t, struct strbuf *base,
124
+ struct diff_options *opt, int *all_interesting)
125
{
126
while (t->size) {
148
- int show = tree_entry_interesting(&t->entry, base, baselen, &opt->pathspec);
127
+ int show = tree_entry_interesting(&t->entry, base, &opt->pathspec);
128
if (show == 2)
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*all_interesting = 1;
130
if (!show) {
@@ -159,37 +138,40 @@ static void skip_uninteresting(struct tree_desc *t, const char *base, int basele
138
}
139
}
140
162
-int diff_tree(struct tree_desc *t1, struct tree_desc *t2, const char *base, struct diff_options *opt)
141
+int diff_tree(struct tree_desc *t1, struct tree_desc *t2,
142
+ const char *base_str, struct diff_options *opt)
143
{
164
- int baselen = strlen(base);
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+ struct strbuf base;
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+ int baselen = strlen(base_str);
146
int all_t1_interesting = 0;
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int all_t2_interesting = 0;
148
149
+ strbuf_init(&base, PATH_MAX);
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+ strbuf_add(&base, base_str, baselen);
151
+
152
for (;;) {
153
if (DIFF_OPT_TST(opt, QUICK) &&
154
DIFF_OPT_TST(opt, HAS_CHANGES))
155
break;
156
if (opt->pathspec.nr) {
157
if (!all_t1_interesting)
174
- skip_uninteresting(t1, base, baselen, opt,
175
- &all_t1_interesting);
158
+ skip_uninteresting(t1, &base, opt, &all_t1_interesting);
159
if (!all_t2_interesting)
177
- skip_uninteresting(t2, base, baselen, opt,
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- &all_t2_interesting);
160
+ skip_uninteresting(t2, &base, opt, &all_t2_interesting);
161
}
162
if (!t1->size) {
163
if (!t2->size)
164
break;
183
- show_entry(opt, "+", t2, base, baselen);
165
+ show_entry(opt, "+", t2, &base);
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update_tree_entry(t2);
167
continue;
168
}
169
if (!t2->size) {
188
- show_entry(opt, "-", t1, base, baselen);
170
+ show_entry(opt, "-", t1, &base);
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update_tree_entry(t1);
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continue;
173
}
192
- switch (compare_tree_entry(t1, t2, base, baselen, opt)) {
174
+ switch (compare_tree_entry(t1, t2, &base, opt)) {
175
case -1:
176
update_tree_entry(t1);
177
continue;
@@ -202,6 +184,8 @@ int diff_tree(struct tree_desc *t1, struct tree_desc *t2, const char *base, stru
184
}
185
die("git diff-tree: internal error");
186
}
187
+
188
+ strbuf_release(&base);
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return 0;
190
}
191
tree-walk.c
+3
-2
@@ -468,12 +468,13 @@ int get_tree_entry(const unsigned char *tree_sha1, const char *name, unsigned ch
468
* - negative for "no, and no subsequent entries will be either"
469
*/
470
int tree_entry_interesting(const struct name_entry *entry,
471
- const char *base, int baselen,
471
+ const struct strbuf *base_buf,
472
const struct pathspec *ps)
473
{
474
int i;
475
- int pathlen;
475
+ int pathlen, baselen = base_buf->len;
476
int never_interesting = -1;
477
+ const char *base = base_buf->buf;
478
479
if (!ps || !ps->nr)
480
return 2;
tree-walk.h
+1
-1
@@ -60,6 +60,6 @@ static inline int traverse_path_len(const struct traverse_info *info, const stru
60
return info->pathlen + tree_entry_len(n->path, n->sha1);
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}
62
63
-extern int tree_entry_interesting(const struct name_entry *, const char *, int, const struct pathspec *ps);
63
+extern int tree_entry_interesting(const struct name_entry *, const struct strbuf *, const struct pathspec *ps);
64
65
#endif