mirrors/git
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

use skip_prefix to avoid magic numbers

Browse Source 
It's a common idiom to match a prefix and then skip past it
with a magic number, like:

  if (starts_with(foo, "bar"))
	  foo += 3;

This is easy to get wrong, since you have to count the
prefix string yourself, and there's no compiler check if the
string changes.  We can use skip_prefix to avoid the magic
numbers here.

Note that some of these conversions could be much shorter.
For example:

  if (starts_with(arg, "--foo=")) {
	  bar = arg + 6;
	  continue;
  }

could become:

  if (skip_prefix(arg, "--foo=", &bar))
	  continue;

However, I have left it as:

  if (skip_prefix(arg, "--foo=", &v)) {
	  bar = v;
	  continue;
  }

to visually match nearby cases which need to actually
process the string. Like:

  if (skip_prefix(arg, "--foo=", &v)) {
	  bar = atoi(v);
	  continue;
  }

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This commit is contained in:
Jeff King
2014-06-18 15:47:50 -04:00
committed by Junio C Hamano
parent 21a2d4ada5
commit ae021d8791
11 changed files with 149 additions and 131 deletions
Download Patch File Download Diff File Expand all files Collapse all files

69
fast-import.c
View File

@ -1912,8 +1912,9 @@ static void skip_optional_lf(void)
static void parse_mark(void)
{
if (starts_with(command_buf.buf, "mark :")) {
next_mark = strtoumax(command_buf.buf + 6, NULL, 10);
const char *v;
if (skip_prefix(command_buf.buf, "mark :", &v)) {
next_mark = strtoumax(v, NULL, 10);
read_next_command();
}
else
@ -1922,14 +1923,15 @@ static void parse_mark(void)
static int parse_data(struct strbuf *sb, uintmax_t limit, uintmax_t *len_res)
{
const char *data;
strbuf_reset(sb);
if (!starts_with(command_buf.buf, "data "))
if (!skip_prefix(command_buf.buf, "data ", &data))
die("Expected 'data n' command, found: %s", command_buf.buf);
if (starts_with(command_buf.buf + 5, "<<")) {
char *term = xstrdup(command_buf.buf + 5 + 2);
size_t term_len = command_buf.len - 5 - 2;
if (skip_prefix(data, "<<", &data)) {
char *term = xstrdup(data);
size_t term_len = command_buf.len - (data - command_buf.buf);
strbuf_detach(&command_buf, NULL);
for (;;) {
@ -1944,7 +1946,7 @@ static int parse_data(struct strbuf *sb, uintmax_t limit, uintmax_t *len_res)
free(term);
}
else {
uintmax_t len = strtoumax(command_buf.buf + 5, NULL, 10);
uintmax_t len = strtoumax(data, NULL, 10);
size_t n = 0, length = (size_t)len;
if (limit && limit < len) {
@ -2676,6 +2678,7 @@ static void parse_new_commit(void)
struct hash_list *merge_list = NULL;
unsigned int merge_count;
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;
@ -2685,12 +2688,12 @@ static void parse_new_commit(void)
read_next_command();
parse_mark();
if (starts_with(command_buf.buf, "author ")) {
author = parse_ident(command_buf.buf + 7);
if (skip_prefix(command_buf.buf, "author ", &v)) {
author = parse_ident(v);
read_next_command();
}
if (starts_with(command_buf.buf, "committer ")) {
committer = parse_ident(command_buf.buf + 10);
if (skip_prefix(command_buf.buf, "committer ", &v)) {
committer = parse_ident(v);
read_next_command();
}
if (!committer)
@ -2777,6 +2780,7 @@ static void parse_new_tag(void)
uintmax_t from_mark = 0;
unsigned char sha1[20];
enum object_type type;
const char *v;
/* Obtain the new tag name from the rest of our command */
sp = strchr(command_buf.buf, ' ') + 1;
@ -2819,8 +2823,8 @@ static void parse_new_tag(void)
read_next_command();
/* tagger ... */
if (starts_with(command_buf.buf, "tagger ")) {
tagger = parse_ident(command_buf.buf + 7);
if (skip_prefix(command_buf.buf, "tagger ", &v)) {
tagger = parse_ident(v);
read_next_command();
} else
tagger = NULL;
@ -3207,9 +3211,9 @@ static void option_export_pack_edges(const char *edges)
static int parse_one_option(const char *option)
{
if (starts_with(option, "max-pack-size=")) {
if (skip_prefix(option, "max-pack-size=", &option)) {
unsigned long v;
if (!git_parse_ulong(option + 14, &v))
if (!git_parse_ulong(option, &v))
return 0;
if (v < 8192) {
warning("max-pack-size is now in bytes, assuming --max-pack-size=%lum", v);
@ -3219,17 +3223,17 @@ static int parse_one_option(const char *option)
v = 1024 * 1024;
}
max_packsize = v;
} else if (starts_with(option, "big-file-threshold=")) {
} else if (skip_prefix(option, "big-file-threshold=", &option)) {
unsigned long v;
if (!git_parse_ulong(option + 19, &v))
if (!git_parse_ulong(option, &v))
return 0;
big_file_threshold = v;
} else if (starts_with(option, "depth=")) {
option_depth(option + 6);
} else if (starts_with(option, "active-branches=")) {
option_active_branches(option + 16);
} else if (starts_with(option, "export-pack-edges=")) {
option_export_pack_edges(option + 18);
} else if (skip_prefix(option, "depth=", &option)) {
option_depth(option);
} else if (skip_prefix(option, "active-branches=", &option)) {
option_active_branches(option);
} else if (skip_prefix(option, "export-pack-edges=", &option)) {
option_export_pack_edges(option);
} else if (starts_with(option, "quiet")) {
show_stats = 0;
} else if (starts_with(option, "stats")) {
@ -3243,15 +3247,16 @@ static int parse_one_option(const char *option)
static int parse_one_feature(const char *feature, int from_stream)
{
if (starts_with(feature, "date-format=")) {
option_date_format(feature + 12);
} else if (starts_with(feature, "import-marks=")) {
option_import_marks(feature + 13, from_stream, 0);
} else if (starts_with(feature, "import-marks-if-exists=")) {
option_import_marks(feature + strlen("import-marks-if-exists="),
from_stream, 1);
} else if (starts_with(feature, "export-marks=")) {
option_export_marks(feature + 13);
const char *arg;
if (skip_prefix(feature, "date-format=", &arg)) {
option_date_format(arg);
} else if (skip_prefix(feature, "import-marks=", &arg)) {
option_import_marks(arg, from_stream, 0);
} else if (skip_prefix(feature, "import-marks-if-exists=", &arg)) {
option_import_marks(arg, from_stream, 1);
} else if (skip_prefix(feature, "export-marks=", &arg)) {
option_export_marks(arg);
} else if (!strcmp(feature, "cat-blob")) {
; /* Don't die - this feature is supported */
} else if (!strcmp(feature, "relative-marks")) {