Support RFC 2822 date parsing in fast-import.

Since some frontends may be working with source material where
the dates are only readily available as RFC 2822 strings, it is
more friendly if fast-import exposes Git's parse_date() function
to handle the conversion.  This way the frontend doesn't need
to perform the parsing itself.

The new --date-format option to fast-import can be used by a
frontend to select which format it will supply date strings in.
The default is the standard `raw` Git format, which fast-import
has always supported.  Format rfc2822 can be used to activate the
parse_date() function instead.

Because fast-import could also be useful for creating new, current
commits, the format `now` is also supported to generate the current
system timestamp.  The implementation of `now` is a trivial call
to datestamp(), but is actually a whole whopping 3 lines so that
fast-import can verify the frontend really meant `now`.

As part of this change I have added validation of the `raw` date
format.  Prior to this change fast-import would accept anything
in a `committer` command, even if it was seriously malformed.
Now fast-import requires the '> ' near the end of the string and
verifies the timestamp is formatted properly.

Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
This commit is contained in:
Shawn O. Pearce 2007-02-06 14:58:30 -05:00
parent ef94edb53c
commit 63e0c8b364
3 changed files with 214 additions and 24 deletions

View File

@ -32,6 +32,12 @@ the frontend program in use.
OPTIONS
-------
--date-format=<fmt>::
Specify the type of dates the frontend will supply to
gfi within `author`, `committer` and `tagger` commands.
See ``Date Formats'' below for details about which formats
are supported, and their syntax.
--max-pack-size=<n>::
Maximum size of each output packfile, expressed in MiB.
The default is 4096 (4 GiB) as that is the maximum allowed
@ -53,7 +59,6 @@ OPTIONS
Frontends can use this file to validate imports after they
have been completed.
Performance
-----------
The design of gfi allows it to import large projects in a minimum
@ -127,6 +132,78 @@ results, such as branch names or file names with leading or trailing
spaces in their name, or early termination of gfi when it encounters
unexpected input.
Date Formats
~~~~~~~~~~~~
The following date formats are supported. A frontend should select
the format it will use for this import by passing the format name
in the `--date-format=<fmt>` command line option.
`raw`::
This is the Git native format and is `<time> SP <tz>`.
It is also gfi's default format, if `--date-format` was
not specified.
+
The time of the event is specified by `<time>` as the number of
seconds since the UNIX epoch (midnight, Jan 1, 1970, UTC) and is
written as an ASCII decimal integer.
+
The timezone is specified by `<tz>` as a positive or negative offset
from UTC. For example EST (which is typically 5 hours behind GMT)
would be expressed in `<tz>` by ``-0500'' while GMT is ``+0000''.
+
If the timezone is not available in the source material, use
``+0000'', or the most common local timezone. For example many
organizations have a CVS repository which has only ever been accessed
by users who are located in the same location and timezone. In this
case the user's timezone can be easily assumed.
+
Unlike the `rfc2822` format, this format is very strict. Any
variation in formatting will cause gfi to reject the value.
`rfc2822`::
This is the standard email format as described by RFC 2822.
+
An example value is ``Tue Feb 6 11:22:18 2007 -0500''. The Git
parser is accurate, but a little on the lenient side. Its the
same parser used by gitlink:git-am[1] when applying patches
received from email.
+
Some malformed strings may be accepted as valid dates. In some of
these cases Git will still be able to obtain the correct date from
the malformed string. There are also some types of malformed
strings which Git will parse wrong, and yet consider valid.
Seriously malformed strings will be rejected.
+
If the source material is formatted in RFC 2822 style dates,
the frontend should let gfi handle the parsing and conversion
(rather than attempting to do it itself) as the Git parser has
been well tested in the wild.
+
Frontends should prefer the `raw` format if the source material
is already in UNIX-epoch format, or is easily convertible to
that format, as there is no ambiguity in parsing.
`now`::
Always use the current time and timezone. The literal
`now` must always be supplied for `<when>`.
+
This is a toy format. The current time and timezone of this system
is always copied into the identity string at the time it is being
created by gfi. There is no way to specify a different time or
timezone.
+
This particular format is supplied as its short to implement and
may be useful to a process that wants to create a new commit
right now, without needing to use a working directory or
gitlink:git-update-index[1].
+
If separate `author` and `committer` commands are used in a `commit`
the timestamps may not match, as the system clock will be polled
twice (once for each command). The only way to ensure that both
author and committer identity information has the same timestamp
is to omit `author` (thus copying from `committer`) or to use a
date format other than `now`.
Commands
~~~~~~~~
gfi accepts several commands to update the current repository
@ -168,8 +245,8 @@ change to the project.
....
'commit' SP <ref> LF
mark?
('author' SP <name> SP LT <email> GT SP <time> SP <tz> LF)?
'committer' SP <name> SP LT <email> GT SP <time> SP <tz> LF
('author' SP <name> SP LT <email> GT SP <when> LF)?
'committer' SP <name> SP LT <email> GT SP <when> LF
data
('from' SP <committish> LF)?
('merge' SP <committish> LF)?
@ -222,12 +299,10 @@ the email address from the other fields in the line. Note that
`<name>` is free-form and may contain any sequence of bytes, except
`LT` and `LF`. It is typically UTF-8 encoded.
The time of the change is specified by `<time>` as the number of
seconds since the UNIX epoc (midnight, Jan 1, 1970, UTC) and is
written as an ASCII decimal integer. The committer's
timezone is specified by `<tz>` as a positive or negative offset
from UTC. For example EST (which is typically 5 hours behind GMT)
would be expressed in `<tz>` by ``-0500'' while GMT is ``+0000''.
The time of the change is specified by `<when>` using the date format
that was selected by the `--date-format=<fmt>` command line option.
See ``Date Formats'' above for the set of supported formats, and
their syntax.
`from`
^^^^^^
@ -394,7 +469,7 @@ lightweight (non-annotated) tags see the `reset` command below.
....
'tag' SP <name> LF
'from' SP <committish> LF
'tagger' SP <name> SP LT <email> GT SP <time> SP <tz> LF
'tagger' SP <name> SP LT <email> GT SP <when> LF
data
LF
....

View File

@ -17,8 +17,8 @@ Format of STDIN stream:
new_commit ::= 'commit' sp ref_str lf
mark?
('author' sp name '<' email '>' ts tz lf)?
'committer' sp name '<' email '>' ts tz lf
('author' sp name '<' email '>' when lf)?
'committer' sp name '<' email '>' when lf
commit_msg
('from' sp (ref_str | hexsha1 | sha1exp_str | idnum) lf)?
('merge' sp (ref_str | hexsha1 | sha1exp_str | idnum) lf)*
@ -34,7 +34,7 @@ Format of STDIN stream:
new_tag ::= 'tag' sp tag_str lf
'from' sp (ref_str | hexsha1 | sha1exp_str | idnum) lf
'tagger' sp name '<' email '>' ts tz lf
'tagger' sp name '<' email '>' when lf
tag_msg;
tag_msg ::= data;
@ -88,6 +88,10 @@ Format of STDIN stream:
bigint ::= # unsigned integer value, ascii base10 notation;
binary_data ::= # file content, not interpreted;
when ::= raw_when | rfc2822_when;
raw_when ::= ts sp tz;
rfc2822_when ::= # Valid RFC 2822 date and time;
sp ::= # ASCII space character;
lf ::= # ASCII newline (LF) character;
@ -234,6 +238,12 @@ struct hash_list
unsigned char sha1[20];
};
typedef enum {
WHENSPEC_RAW = 1,
WHENSPEC_RFC2822,
WHENSPEC_NOW,
} whenspec_type;
/* Configured limits on output */
static unsigned long max_depth = 10;
static unsigned long max_packsize = (1LL << 32) - 1;
@ -294,6 +304,7 @@ static struct tag *first_tag;
static struct tag *last_tag;
/* Input stream parsing */
static whenspec_type whenspec = WHENSPEC_RAW;
static struct strbuf command_buf;
static uintmax_t next_mark;
static struct dbuf new_data;
@ -1396,6 +1407,64 @@ static void *cmd_data (size_t *size)
return buffer;
}
static int validate_raw_date(const char *src, char *result, int maxlen)
{
const char *orig_src = src;
char *endp, sign;
strtoul(src, &endp, 10);
if (endp == src || *endp != ' ')
return -1;
src = endp + 1;
if (*src != '-' && *src != '+')
return -1;
sign = *src;
strtoul(src + 1, &endp, 10);
if (endp == src || *endp || (endp - orig_src) >= maxlen)
return -1;
strcpy(result, orig_src);
return 0;
}
static char *parse_ident(const char *buf)
{
const char *gt;
size_t name_len;
char *ident;
gt = strrchr(buf, '>');
if (!gt)
die("Missing > in ident string: %s", buf);
gt++;
if (*gt != ' ')
die("Missing space after > in ident string: %s", buf);
gt++;
name_len = gt - buf;
ident = xmalloc(name_len + 24);
strncpy(ident, buf, name_len);
switch (whenspec) {
case WHENSPEC_RAW:
if (validate_raw_date(gt, ident + name_len, 24) < 0)
die("Invalid raw date \"%s\" in ident: %s", gt, buf);
break;
case WHENSPEC_RFC2822:
if (parse_date(gt, ident + name_len, 24) < 0)
die("Invalid rfc2822 date \"%s\" in ident: %s", gt, buf);
break;
case WHENSPEC_NOW:
if (strcmp("now", gt))
die("Date in ident must be 'now': %s", buf);
datestamp(ident + name_len, 24);
break;
}
return ident;
}
static void cmd_new_blob(void)
{
size_t l;
@ -1655,11 +1724,11 @@ static void cmd_new_commit(void)
read_next_command();
cmd_mark();
if (!strncmp("author ", command_buf.buf, 7)) {
author = strdup(command_buf.buf);
author = parse_ident(command_buf.buf + 7);
read_next_command();
}
if (!strncmp("committer ", command_buf.buf, 10)) {
committer = strdup(command_buf.buf);
committer = parse_ident(command_buf.buf + 10);
read_next_command();
}
if (!committer)
@ -1692,7 +1761,7 @@ static void cmd_new_commit(void)
store_tree(&b->branch_tree);
hashcpy(b->branch_tree.versions[0].sha1,
b->branch_tree.versions[1].sha1);
size_dbuf(&new_data, 97 + msglen
size_dbuf(&new_data, 114 + msglen
+ merge_count * 49
+ (author
? strlen(author) + strlen(committer)
@ -1708,11 +1777,9 @@ static void cmd_new_commit(void)
free(merge_list);
merge_list = next;
}
if (author)
sp += sprintf(sp, "%s\n", author);
else
sp += sprintf(sp, "author %s\n", committer + 10);
sp += sprintf(sp, "%s\n\n", committer);
sp += sprintf(sp, "author %s\n", author ? author : committer);
sp += sprintf(sp, "committer %s\n", committer);
*sp++ = '\n';
memcpy(sp, msg, msglen);
sp += msglen;
free(author);
@ -1780,7 +1847,7 @@ static void cmd_new_tag(void)
/* tagger ... */
if (strncmp("tagger ", command_buf.buf, 7))
die("Expected tagger command, got %s", command_buf.buf);
tagger = strdup(command_buf.buf);
tagger = parse_ident(command_buf.buf + 7);
/* tag payload/message */
read_next_command();
@ -1792,7 +1859,8 @@ static void cmd_new_tag(void)
sp += sprintf(sp, "object %s\n", sha1_to_hex(sha1));
sp += sprintf(sp, "type %s\n", type_names[OBJ_COMMIT]);
sp += sprintf(sp, "tag %s\n", t->name);
sp += sprintf(sp, "%s\n\n", tagger);
sp += sprintf(sp, "tagger %s\n", tagger);
*sp++ = '\n';
memcpy(sp, msg, msglen);
sp += msglen;
free(tagger);
@ -1835,7 +1903,7 @@ static void cmd_checkpoint(void)
}
static const char fast_import_usage[] =
"git-fast-import [--depth=n] [--active-branches=n] [--export-marks=marks.file] [--branch-log=log]";
"git-fast-import [--date-format=f] [--max-pack-size=n] [--depth=n] [--active-branches=n] [--export-marks=marks.file]";
int main(int argc, const char **argv)
{
@ -1849,6 +1917,17 @@ int main(int argc, const char **argv)
if (*a != '-' || !strcmp(a, "--"))
break;
else if (!strncmp(a, "--date-format=", 14)) {
const char *fmt = a + 14;
if (!strcmp(fmt, "raw"))
whenspec = WHENSPEC_RAW;
else if (!strcmp(fmt, "rfc2822"))
whenspec = WHENSPEC_RFC2822;
else if (!strcmp(fmt, "now"))
whenspec = WHENSPEC_NOW;
else
die("unknown --date-format argument %s", fmt);
}
else if (!strncmp(a, "--max-pack-size=", 16))
max_packsize = strtoumax(a + 16, NULL, 0) * 1024 * 1024;
else if (!strncmp(a, "--depth=", 8))

View File

@ -240,4 +240,40 @@ test_expect_success \
'git-cat-file blob branch:newdir/exec.sh >actual &&
diff -u expect actual'
###
### series E
###
cat >input <<INPUT_END
commit refs/heads/branch
author $GIT_AUTHOR_NAME <$GIT_AUTHOR_EMAIL> Tue Feb 6 11:22:18 2007 -0500
committer $GIT_COMMITTER_NAME <$GIT_COMMITTER_EMAIL> Tue Feb 6 12:35:02 2007 -0500
data <<COMMIT
RFC 2822 type date
COMMIT
from refs/heads/branch^0
INPUT_END
test_expect_failure \
'E: rfc2822 date, --date-format=raw' \
'git-fast-import --date-format=raw <input'
test_expect_success \
'E: rfc2822 date, --date-format=rfc2822' \
'git-fast-import --date-format=rfc2822 <input'
test_expect_success \
'E: verify pack' \
'for p in .git/objects/pack/*.pack;do git-verify-pack $p||exit;done'
cat >expect <<EOF
author $GIT_AUTHOR_NAME <$GIT_AUTHOR_EMAIL> 1170778938 -0500
committer $GIT_COMMITTER_NAME <$GIT_COMMITTER_EMAIL> 1170783302 -0500
RFC 2822 type date
EOF
test_expect_success \
'E: verify commit' \
'git-cat-file commit branch | sed 1,2d >actual &&
diff -u expect actual'
test_done