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Merge branch 'jc/attr'

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* jc/attr:
  Add 'filter' attribute and external filter driver definition.
  Add 'ident' conversion.
This commit is contained in:
Junio C Hamano 2007-04-29 11:01:27 -07:00
commit a07157ac62
3 changed files with 531 additions and 12 deletions
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70
Documentation/gitattributes.txt
View File

@ -78,12 +78,17 @@ are attributes-aware.
Checking-out and checking-in Checking-out and checking-in
~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~
The attribute `crlf` affects how the contents stored in the These attributes affect how the contents stored in the
repository are copied to the working tree files when commands repository are copied to the working tree files when commands
such as `git checkout` and `git merge` run. It also affects how such as `git checkout` and `git merge` run. They also affect how
git stores the contents you prepare in the working tree in the git stores the contents you prepare in the working tree in the
repository upon `git add` and `git commit`. repository upon `git add` and `git commit`.
`crlf`
^^^^^^
This attribute controls the line-ending convention.
Set:: Set::
Setting the `crlf` attribute on a path is meant to mark Setting the `crlf` attribute on a path is meant to mark
@ -129,6 +134,67 @@ converted to LF upon checkin, but there is no conversion done
upon checkout. upon checkout.
`ident`
^^^^^^^
When the attribute `ident` is set to a path, git replaces
`$ident$` in the blob object with `$ident:`, followed by
40-character hexadecimal blob object name, followed by a dollar
sign `$` upon checkout. Any byte sequence that begins with
`$ident:` and ends with `$` in the worktree file is replaced
with `$ident$` upon check-in.
Interaction between checkin/checkout attributes
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
In the check-in codepath, the worktree file is first converted
with `ident` (if specified), and then with `crlf` (again, if
specified and applicable).
In the check-out codepath, the blob content is first converted
with `crlf`, and then `ident`.
`filter`
^^^^^^^^
A `filter` attribute can be set to a string value. This names
filter driver specified in the configuration.
A filter driver consists of `clean` command and `smudge`
command, either of which can be left unspecified. Upon
checkout, when `smudge` command is specified, the command is fed
the blob object from its standard input, and its standard output
is used to update the worktree file. Similarly, `clean` command
is used to convert the contents of worktree file upon checkin.
Missing filter driver definition in the config is not an error
but makes the filter a no-op passthru.
The content filtering is done to massage the content into a
shape that is more convenient for the platform, filesystem, and
the user to use. The keyword here is "more convenient" and not
"turning something unusable into usable". In other words, it is
"hanging yourself because we gave you a long rope" if your
project uses filtering mechanism in such a way that it makes
your project unusable unless the checkout is done with a
specific filter in effect.
Interaction between checkin/checkout attributes
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
In the check-in codepath, the worktree file is first converted
with `filter` driver (if specified and corresponding driver
defined), then the result is processed with `ident` (if
specified), and then finally with `crlf` (again, if specified
and applicable).
In the check-out codepath, the blob content is first converted
with `crlf`, and then `ident` and fed to `filter`.
Generating diff text Generating diff text
~~~~~~~~~~~~~~~~~~~~ ~~~~~~~~~~~~~~~~~~~~

425
convert.c
View File

@ -1,5 +1,6 @@
#include "cache.h" #include "cache.h"
#include "attr.h" #include "attr.h"
#include "run-command.h"
/* /*
* convert.c - convert a file when checking it out and checking it in. * convert.c - convert a file when checking it out and checking it in.
@ -200,13 +201,350 @@ static char *crlf_to_worktree(const char *path, const char *src, unsigned long *
return buffer; return buffer;
} }
static int filter_buffer(const char *path, const char *src,
unsigned long size, const char *cmd)
{
/*
* Spawn cmd and feed the buffer contents through its stdin.
*/
struct child_process child_process;
int pipe_feed[2];
int write_err, status;
memset(&child_process, 0, sizeof(child_process));
if (pipe(pipe_feed) < 0) {
error("cannot create pipe to run external filter %s", cmd);
return 1;
}
child_process.pid = fork();
if (child_process.pid < 0) {
error("cannot fork to run external filter %s", cmd);
close(pipe_feed[0]);
close(pipe_feed[1]);
return 1;
}
if (!child_process.pid) {
dup2(pipe_feed[0], 0);
close(pipe_feed[0]);
close(pipe_feed[1]);
execlp("sh", "sh", "-c", cmd, NULL);
return 1;
}
close(pipe_feed[0]);
write_err = (write_in_full(pipe_feed[1], src, size) < 0);
if (close(pipe_feed[1]))
write_err = 1;
if (write_err)
error("cannot feed the input to external filter %s", cmd);
status = finish_command(&child_process);
if (status)
error("external filter %s failed %d", cmd, -status);
return (write_err || status);
}
static char *apply_filter(const char *path, const char *src,
unsigned long *sizep, const char *cmd)
{
/*
* Create a pipeline to have the command filter the buffer's
* contents.
*
* (child --> cmd) --> us
*/
const int SLOP = 4096;
int pipe_feed[2];
int status;
char *dst;
unsigned long dstsize, dstalloc;
struct child_process child_process;
if (!cmd)
return NULL;
memset(&child_process, 0, sizeof(child_process));
if (pipe(pipe_feed) < 0) {
error("cannot create pipe to run external filter %s", cmd);
return NULL;
}
fflush(NULL);
child_process.pid = fork();
if (child_process.pid < 0) {
error("cannot fork to run external filter %s", cmd);
close(pipe_feed[0]);
close(pipe_feed[1]);
return NULL;
}
if (!child_process.pid) {
dup2(pipe_feed[1], 1);
close(pipe_feed[0]);
close(pipe_feed[1]);
exit(filter_buffer(path, src, *sizep, cmd));
}
close(pipe_feed[1]);
dstalloc = *sizep;
dst = xmalloc(dstalloc);
dstsize = 0;
while (1) {
ssize_t numread = xread(pipe_feed[0], dst + dstsize,
dstalloc - dstsize);
if (numread <= 0) {
if (!numread)
break;
error("read from external filter %s failed", cmd);
free(dst);
dst = NULL;
break;
}
dstsize += numread;
if (dstalloc <= dstsize + SLOP) {
dstalloc = dstsize + SLOP;
dst = xrealloc(dst, dstalloc);
}
}
if (close(pipe_feed[0])) {
error("read from external filter %s failed", cmd);
free(dst);
dst = NULL;
}
status = finish_command(&child_process);
if (status) {
error("external filter %s failed %d", cmd, -status);
free(dst);
dst = NULL;
}
if (dst)
*sizep = dstsize;
return dst;
}
static struct convert_driver {
const char *name;
struct convert_driver *next;
char *smudge;
char *clean;
} *user_convert, **user_convert_tail;
static int read_convert_config(const char *var, const char *value)
{
const char *ep, *name;
int namelen;
struct convert_driver *drv;
/*
* External conversion drivers are configured using
* "filter.<name>.variable".
*/
if (prefixcmp(var, "filter.") || (ep = strrchr(var, '.')) == var + 6)
return 0;
name = var + 7;
namelen = ep - name;
for (drv = user_convert; drv; drv = drv->next)
if (!strncmp(drv->name, name, namelen) && !drv->name[namelen])
break;
if (!drv) {
char *namebuf;
drv = xcalloc(1, sizeof(struct convert_driver));
namebuf = xmalloc(namelen + 1);
memcpy(namebuf, name, namelen);
namebuf[namelen] = 0;
drv->name = namebuf;
drv->next = NULL;
*user_convert_tail = drv;
user_convert_tail = &(drv->next);
}
ep++;
/*
* filter.<name>.smudge and filter.<name>.clean specifies
* the command line:
*
* command-line
*
* The command-line will not be interpolated in any way.
*/
if (!strcmp("smudge", ep)) {
if (!value)
return error("%s: lacks value", var);
drv->smudge = strdup(value);
return 0;
}
if (!strcmp("clean", ep)) {
if (!value)
return error("%s: lacks value", var);
drv->clean = strdup(value);
return 0;
}
return 0;
}
static void setup_convert_check(struct git_attr_check *check) static void setup_convert_check(struct git_attr_check *check)
{ {
static struct git_attr *attr_crlf; static struct git_attr *attr_crlf;
static struct git_attr *attr_ident;
static struct git_attr *attr_filter;
if (!attr_crlf) if (!attr_crlf) {
attr_crlf = git_attr("crlf", 4); attr_crlf = git_attr("crlf", 4);
check->attr = attr_crlf; attr_ident = git_attr("ident", 5);
attr_filter = git_attr("filter", 6);
user_convert_tail = &user_convert;
git_config(read_convert_config);
}
check[0].attr = attr_crlf;
check[1].attr = attr_ident;
check[2].attr = attr_filter;
}
static int count_ident(const char *cp, unsigned long size)
{
/*
* "$ident: 0000000000000000000000000000000000000000 $" <=> "$ident$"
*/
int cnt = 0;
char ch;
while (size) {
ch = *cp++;
size--;
if (ch != '$')
continue;
if (size < 6)
break;
if (memcmp("ident", cp, 5))
continue;
ch = cp[5];
cp += 6;
size -= 6;
if (ch == '$')
cnt++; /* $ident$ */
if (ch != ':')
continue;
/*
* "$ident: ... "; scan up to the closing dollar sign and discard.
*/
while (size) {
ch = *cp++;
size--;
if (ch == '$') {
cnt++;
break;
}
}
}
return cnt;
}
static char *ident_to_git(const char *path, const char *src, unsigned long *sizep, int ident)
{
int cnt;
unsigned long size;
char *dst, *buf;
if (!ident)
return NULL;
size = *sizep;
cnt = count_ident(src, size);
if (!cnt)
return NULL;
buf = xmalloc(size);
for (dst = buf; size; size--) {
char ch = *src++;
*dst++ = ch;
if ((ch == '$') && (6 <= size) &&
!memcmp("ident:", src, 6)) {
unsigned long rem = size - 6;
const char *cp = src + 6;
do {
ch = *cp++;
if (ch == '$')
break;
rem--;
} while (rem);
if (!rem)
continue;
memcpy(dst, "ident$", 6);
dst += 6;
size -= (cp - src);
src = cp;
}
}
*sizep = dst - buf;
return buf;
}
static char *ident_to_worktree(const char *path, const char *src, unsigned long *sizep, int ident)
{
int cnt;
unsigned long size;
char *dst, *buf;
unsigned char sha1[20];
if (!ident)
return NULL;
size = *sizep;
cnt = count_ident(src, size);
if (!cnt)
return NULL;
hash_sha1_file(src, size, "blob", sha1);
buf = xmalloc(size + cnt * 43);
for (dst = buf; size; size--) {
const char *cp;
char ch = *src++;
*dst++ = ch;
if ((ch != '$') || (size < 6) || memcmp("ident", src, 5))
continue;
if (src[5] == ':') {
/* discard up to but not including the closing $ */
unsigned long rem = size - 6;
cp = src + 6;
do {
ch = *cp++;
if (ch == '$')
break;
rem--;
} while (rem);
if (!rem)
continue;
size -= (cp - src);
} else if (src[5] == '$')
cp = src + 5;
else
continue;
memcpy(dst, "ident: ", 7);
dst += 7;
memcpy(dst, sha1_to_hex(sha1), 40);
dst += 40;
*dst++ = ' ';
size -= (cp - src);
src = cp;
*dst++ = *src++;
size--;
}
*sizep = dst - buf;
return buf;
} }
static int git_path_check_crlf(const char *path, struct git_attr_check *check) static int git_path_check_crlf(const char *path, struct git_attr_check *check)
@ -224,26 +562,93 @@ static int git_path_check_crlf(const char *path, struct git_attr_check *check)
return CRLF_GUESS; return CRLF_GUESS;
} }
static struct convert_driver *git_path_check_convert(const char *path,
struct git_attr_check *check)
{
const char *value = check->value;
struct convert_driver *drv;
if (ATTR_TRUE(value) || ATTR_FALSE(value) || ATTR_UNSET(value))
return NULL;
for (drv = user_convert; drv; drv = drv->next)
if (!strcmp(value, drv->name))
return drv;
return NULL;
}
static int git_path_check_ident(const char *path, struct git_attr_check *check)
{
const char *value = check->value;
return !!ATTR_TRUE(value);
}
char *convert_to_git(const char *path, const char *src, unsigned long *sizep) char *convert_to_git(const char *path, const char *src, unsigned long *sizep)
{ {
struct git_attr_check check[1]; struct git_attr_check check[3];
int crlf = CRLF_GUESS; int crlf = CRLF_GUESS;
int ident = 0;
char *filter = NULL;
char *buf, *buf2;
setup_convert_check(check); setup_convert_check(check);
if (!git_checkattr(path, 1, check)) { if (!git_checkattr(path, ARRAY_SIZE(check), check)) {
crlf = git_path_check_crlf(path, check); struct convert_driver *drv;
crlf = git_path_check_crlf(path, check + 0);
ident = git_path_check_ident(path, check + 1);
drv = git_path_check_convert(path, check + 2);
if (drv && drv->clean)
filter = drv->clean;
} }
return crlf_to_git(path, src, sizep, crlf);
buf = apply_filter(path, src, sizep, filter);
buf2 = crlf_to_git(path, buf ? buf : src, sizep, crlf);
if (buf2) {
free(buf);
buf = buf2;
}
buf2 = ident_to_git(path, buf ? buf : src, sizep, ident);
if (buf2) {
free(buf);
buf = buf2;
}
return buf;
} }
char *convert_to_working_tree(const char *path, const char *src, unsigned long *sizep) char *convert_to_working_tree(const char *path, const char *src, unsigned long *sizep)
{ {
struct git_attr_check check[1]; struct git_attr_check check[3];
int crlf = CRLF_GUESS; int crlf = CRLF_GUESS;
int ident = 0;
char *filter = NULL;
char *buf, *buf2;
setup_convert_check(check); setup_convert_check(check);
if (!git_checkattr(path, 1, check)) { if (!git_checkattr(path, ARRAY_SIZE(check), check)) {
crlf = git_path_check_crlf(path, check); struct convert_driver *drv;
crlf = git_path_check_crlf(path, check + 0);
ident = git_path_check_ident(path, check + 1);
drv = git_path_check_convert(path, check + 2);
if (drv && drv->smudge)
filter = drv->smudge;
} }
return crlf_to_worktree(path, src, sizep, crlf);
buf = ident_to_worktree(path, src, sizep, ident);
buf2 = crlf_to_worktree(path, buf ? buf : src, sizep, crlf);
if (buf2) {
free(buf);
buf = buf2;
}
buf2 = apply_filter(path, buf ? buf : src, sizep, filter);
if (buf2) {
free(buf);
buf = buf2;
}
return buf;
} }

48
t/t0021-conversion.sh Executable file
View File

@ -0,0 +1,48 @@
#!/bin/sh
test_description='blob conversion via gitattributes'
. ./test-lib.sh
cat <<\EOF >rot13.sh
tr '[a-zA-Z]' '[n-za-mN-ZA-M]'
EOF
chmod +x rot13.sh
test_expect_success setup '
git config filter.rot13.smudge ./rot13.sh &&
git config filter.rot13.clean ./rot13.sh &&
{
echo "*.t filter=rot13"
echo "*.i ident"
} >.gitattributes &&
{
echo a b c d e f g h i j k l m
echo n o p q r s t u v w x y z
echo '\''$ident$'\''
} >test &&
cat test >test.t &&
cat test >test.o &&
cat test >test.i &&
git add test test.t test.i &&
rm -f test test.t test.i &&
git checkout -- test test.t test.i
'
script='s/^\$ident: \([0-9a-f]*\) \$/\1/p'
test_expect_success check '
cmp test.o test &&
cmp test.o test.t &&
# ident should be stripped in the repository
git diff --raw --exit-code :test :test.i &&
id=$(git rev-parse --verify :test) &&
embedded=$(sed -ne "$script" test.i) &&
test "z$id" = "z$embedded"
'
test_done