Fast-import does a lot of parsing of commands and
dispatching to sub-functions. For example, given "option
foo", we might recognize "option " using starts_with, and
then hand it off to parse_option() to do the rest.
However, we do not let parse_option know that we have parsed
the first part already. It gets the full buffer, and has to
skip past the uninteresting bits. Some functions simply add
a magic constant:
char *option = command_buf.buf + 7;
Others use strlen:
char *option = command_buf.buf + strlen("option ");
And others use strchr:
char *option = strchr(command_buf.buf, ' ') + 1;
All of these are brittle and easy to get wrong (especially
given that the starts_with call and the code that assumes
the presence of the prefix are far apart). Instead, we can
use skip_prefix, and just pass each handler a pointer to its
arguments.
Signed-off-by: Jeff King <peff@xxxxxxxx>
---
fast-import.c | 125 +++++++++++++++++++++++++---------------------------------
1 file changed, 53 insertions(+), 72 deletions(-)
diff --git a/fast-import.c b/fast-import.c
index a3ffe30..5f17adb 100644
--- a/fast-import.c
+++ b/fast-import.c
@@ -371,8 +371,8 @@ static volatile sig_atomic_t checkpoint_requested;
static int cat_blob_fd = STDOUT_FILENO;
static void parse_argv(void);
-static void parse_cat_blob(void);
-static void parse_ls(struct branch *b);
+static void parse_cat_blob(const char *p);
+static void parse_ls(const char *p, struct branch *b);
static void write_branch_report(FILE *rpt, struct branch *b)
{
@@ -1861,6 +1861,8 @@ static int read_next_command(void)
}
for (;;) {
+ const char *p;
+
if (unread_command_buf) {
unread_command_buf = 0;
} else {
@@ -1893,8 +1895,8 @@ static int read_next_command(void)
rc->prev->next = rc;
cmd_tail = rc;
}
- if (starts_with(command_buf.buf, "cat-blob ")) {
- parse_cat_blob();
+ if (skip_prefix(command_buf.buf, "cat-blob ", &p)) {
+ parse_cat_blob(p);
continue;
}
if (command_buf.buf[0] == '#')
@@ -2273,9 +2275,8 @@ static uintmax_t parse_mark_ref_space(const char **p)
return mark;
}
-static void file_change_m(struct branch *b)
+static void file_change_m(const char *p, struct branch *b)
{
- const char *p = command_buf.buf + 2;
static struct strbuf uq = STRBUF_INIT;
const char *endp;
struct object_entry *oe;
@@ -2376,9 +2377,8 @@ static void file_change_m(struct branch *b)
tree_content_set(&b->branch_tree, p, sha1, mode, NULL);
}
-static void file_change_d(struct branch *b)
+static void file_change_d(const char *p, struct branch *b)
{
- const char *p = command_buf.buf + 2;
static struct strbuf uq = STRBUF_INIT;
const char *endp;
@@ -2391,15 +2391,14 @@ static void file_change_d(struct branch *b)
tree_content_remove(&b->branch_tree, p, NULL, 1);
}
-static void file_change_cr(struct branch *b, int rename)
+static void file_change_cr(const char *s, struct branch *b, int rename)
{
- const char *s, *d;
+ const char *d;
static struct strbuf s_uq = STRBUF_INIT;
static struct strbuf d_uq = STRBUF_INIT;
const char *endp;
struct tree_entry leaf;
- s = command_buf.buf + 2;
strbuf_reset(&s_uq);
if (!unquote_c_style(&s_uq, s, &endp)) {
if (*endp != ' ')
@@ -2444,9 +2443,8 @@ static void file_change_cr(struct branch *b, int rename)
leaf.tree);
}
-static void note_change_n(struct branch *b, unsigned char *old_fanout)
+static void note_change_n(const char *p, struct branch *b, unsigned char *old_fanout)
{
- const char *p = command_buf.buf + 2;
static struct strbuf uq = STRBUF_INIT;
struct object_entry *oe;
struct branch *s;
@@ -2587,7 +2585,7 @@ static int parse_from(struct branch *b)
const char *from;
struct branch *s;
- if (!starts_with(command_buf.buf, "from "))
+ if (!skip_prefix(command_buf.buf, "from ", &from))
return 0;
if (b->branch_tree.tree) {
@@ -2595,7 +2593,6 @@ static int parse_from(struct branch *b)
b->branch_tree.tree = NULL;
}
- from = strchr(command_buf.buf, ' ') + 1;
s = lookup_branch(from);
if (b == s)
die("Can't create a branch from itself: %s", b->name);
@@ -2636,8 +2633,7 @@ static struct hash_list *parse_merge(unsigned int *count)
struct branch *s;
*count = 0;
- while (starts_with(command_buf.buf, "merge ")) {
- from = strchr(command_buf.buf, ' ') + 1;
+ while (skip_prefix(command_buf.buf, "merge ", &from)) {
n = xmalloc(sizeof(*n));
s = lookup_branch(from);
if (s)
@@ -2668,11 +2664,10 @@ static struct hash_list *parse_merge(unsigned int *count)
return list;
}
-static void parse_new_commit(void)
+static void parse_new_commit(const char *arg)
{
static struct strbuf msg = STRBUF_INIT;
struct branch *b;
- char *sp;
char *author = NULL;
char *committer = NULL;
struct hash_list *merge_list = NULL;
@@ -2680,11 +2675,9 @@ static void parse_new_commit(void)
unsigned char prev_fanout, new_fanout;
const char *v;
- /* Obtain the branch name from the rest of our command */
- sp = strchr(command_buf.buf, ' ') + 1;
- b = lookup_branch(sp);
+ b = lookup_branch(arg);
if (!b)
- b = new_branch(sp);
+ b = new_branch(arg);
read_next_command();
parse_mark();
@@ -2713,20 +2706,22 @@ static void parse_new_commit(void)
/* file_change* */
while (command_buf.len > 0) {
- if (starts_with(command_buf.buf, "M "))
- file_change_m(b);
- else if (starts_with(command_buf.buf, "D "))
- file_change_d(b);
- else if (starts_with(command_buf.buf, "R "))
- file_change_cr(b, 1);
- else if (starts_with(command_buf.buf, "C "))
- file_change_cr(b, 0);
- else if (starts_with(command_buf.buf, "N "))
- note_change_n(b, &prev_fanout);
+ const char *v;
+
+ if (skip_prefix(command_buf.buf, "M ", &v))
+ file_change_m(v, b);
+ else if (skip_prefix(command_buf.buf, "D ", &v))
+ file_change_d(v, b);
+ else if (skip_prefix(command_buf.buf, "R ", &v))
+ file_change_cr(v, b, 1);
+ else if (skip_prefix(command_buf.buf, "C ", &v))
+ file_change_cr(v, b, 0);
+ else if (skip_prefix(command_buf.buf, "N ", &v))
+ note_change_n(v, b, &prev_fanout);
else if (!strcmp("deleteall", command_buf.buf))
file_change_deleteall(b);
- else if (starts_with(command_buf.buf, "ls "))
- parse_ls(b);
+ else if (skip_prefix(command_buf.buf, "ls ", &v))
+ parse_ls(v, b);
else {
unread_command_buf = 1;
break;
@@ -2769,10 +2764,9 @@ static void parse_new_commit(void)
b->last_commit = object_count_by_type[OBJ_COMMIT];
}
-static void parse_new_tag(void)
+static void parse_new_tag(const char *arg)
{
static struct strbuf msg = STRBUF_INIT;
- char *sp;
const char *from;
char *tagger;
struct branch *s;
@@ -2782,11 +2776,9 @@ static void parse_new_tag(void)
enum object_type type;
const char *v;
- /* Obtain the new tag name from the rest of our command */
- sp = strchr(command_buf.buf, ' ') + 1;
t = pool_alloc(sizeof(struct tag));
memset(t, 0, sizeof(struct tag));
- t->name = pool_strdup(sp);
+ t->name = pool_strdup(arg);
if (last_tag)
last_tag->next_tag = t;
else
@@ -2795,9 +2787,8 @@ static void parse_new_tag(void)
read_next_command();
/* from ... */
- if (!starts_with(command_buf.buf, "from "))
+ if (!skip_prefix(command_buf.buf, "from ", &from))
die("Expected from command, got %s", command_buf.buf);
- from = strchr(command_buf.buf, ' ') + 1;
s = lookup_branch(from);
if (s) {
if (is_null_sha1(s->sha1))
@@ -2853,14 +2844,11 @@ static void parse_new_tag(void)
t->pack_id = pack_id;
}
-static void parse_reset_branch(void)
+static void parse_reset_branch(const char *arg)
{
struct branch *b;
- char *sp;
- /* Obtain the branch name from the rest of our command */
- sp = strchr(command_buf.buf, ' ') + 1;
- b = lookup_branch(sp);
+ b = lookup_branch(arg);
if (b) {
hashclr(b->sha1);
hashclr(b->branch_tree.versions[0].sha1);
@@ -2871,7 +2859,7 @@ static void parse_reset_branch(void)
}
}
else
- b = new_branch(sp);
+ b = new_branch(arg);
read_next_command();
parse_from(b);
if (command_buf.len > 0)
@@ -2929,14 +2917,12 @@ static void cat_blob(struct object_entry *oe, unsigned char sha1[20])
free(buf);
}
-static void parse_cat_blob(void)
+static void parse_cat_blob(const char *p)
{
- const char *p;
struct object_entry *oe = oe;
unsigned char sha1[20];
/* cat-blob SP <object> LF */
- p = command_buf.buf + strlen("cat-blob ");
if (*p == ':') {
oe = find_mark(parse_mark_ref_eol(p));
if (!oe)
@@ -3053,14 +3039,12 @@ static void print_ls(int mode, const unsigned char *sha1, const char *path)
cat_blob_write(line.buf, line.len);
}
-static void parse_ls(struct branch *b)
+static void parse_ls(const char *p, struct branch *b)
{
- const char *p;
struct tree_entry *root = NULL;
struct tree_entry leaf = {NULL};
/* ls SP (<tree-ish> SP)? <path> */
- p = command_buf.buf + strlen("ls ");
if (*p == '"') {
if (!b)
die("Not in a commit: %s", command_buf.buf);
@@ -3276,10 +3260,8 @@ static int parse_one_feature(const char *feature, int from_stream)
return 1;
}
-static void parse_feature(void)
+static void parse_feature(const char *feature)
{
- char *feature = command_buf.buf + 8;
-
if (seen_data_command)
die("Got feature command '%s' after data command", feature);
@@ -3289,10 +3271,8 @@ static void parse_feature(void)
die("This version of fast-import does not support feature %s.", feature);
}
-static void parse_option(void)
+static void parse_option(const char *option)
{
- char *option = command_buf.buf + 11;
-
if (seen_data_command)
die("Got option command '%s' after data command", option);
@@ -3408,26 +3388,27 @@ int main(int argc, char **argv)
set_die_routine(die_nicely);
set_checkpoint_signal();
while (read_next_command() != EOF) {
+ const char *v;
if (!strcmp("blob", command_buf.buf))
parse_new_blob();
- else if (starts_with(command_buf.buf, "ls "))
- parse_ls(NULL);
- else if (starts_with(command_buf.buf, "commit "))
- parse_new_commit();
- else if (starts_with(command_buf.buf, "tag "))
- parse_new_tag();
- else if (starts_with(command_buf.buf, "reset "))
- parse_reset_branch();
+ else if (skip_prefix(command_buf.buf, "ls ", &v))
+ parse_ls(v, NULL);
+ else if (skip_prefix(command_buf.buf, "commit ", &v))
+ parse_new_commit(v);
+ else if (skip_prefix(command_buf.buf, "tag ", &v))
+ parse_new_tag(v);
+ else if (skip_prefix(command_buf.buf, "reset ", &v))
+ parse_reset_branch(v);
else if (!strcmp("checkpoint", command_buf.buf))
parse_checkpoint();
else if (!strcmp("done", command_buf.buf))
break;
else if (starts_with(command_buf.buf, "progress "))
parse_progress();
- else if (starts_with(command_buf.buf, "feature "))
- parse_feature();
- else if (starts_with(command_buf.buf, "option git "))
- parse_option();
+ else if (skip_prefix(command_buf.buf, "feature ", &v))
+ parse_feature(v);
+ else if (skip_prefix(command_buf.buf, "option git ", &v))
+ parse_option(v);
else if (starts_with(command_buf.buf, "option "))
/* ignore non-git options*/;
else
--
2.0.0.566.gfe3e6b2
--
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