The interface is similar to the custom low-level merge drivers.
First you configure your filter driver by defining 'filter.<name>.*'
variables in the configuration.
filter.<name>.clean filter command to run upon checkin
filter.<name>.smudge filter command to run upon checkout
Then you assign filter attribute to each path, whose name
matches the custom filter driver's name.
Example:
(in .gitattributes)
*.c filter=indent
(in config)
[filter "indent"]
clean = indent
smudge = cat
Signed-off-by: Junio C Hamano <junkio@xxxxxxx>
---
convert.c | 259 +++++++++++++++++++++++++++++++++++++++++++++++++++--
t/t0021-filter.sh | 36 ++++++++
2 files changed, 286 insertions(+), 9 deletions(-)
create mode 100755 t/t0021-filter.sh
diff --git a/convert.c b/convert.c
index 37239ac..1fa8f2a 100644
--- a/convert.c
+++ b/convert.c
@@ -1,5 +1,6 @@
#include "cache.h"
#include "attr.h"
+#include "run-command.h"
/*
* convert.c - convert a file when checking it out and checking it in.
@@ -200,18 +201,214 @@ static char *crlf_to_worktree(const char *path, const char *src, unsigned long *
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(cmd, cmd, NULL);
+ return 1;
+ }
+ close(pipe_feed[0]);
+ close(1);
+
+ 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;
+ }
+
+ 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 struct git_attr *attr_crlf;
+ static struct git_attr *attr_filter;
- if (!attr_crlf)
+ if (!attr_crlf) {
attr_crlf = git_attr("crlf", 4);
- check->attr = attr_crlf;
+ 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_filter;
}
static int git_path_check_crlf(const char *path, struct git_attr_check *check)
{
- const char *value = check->value;
+ const char *value = check[0].value;
if (ATTR_TRUE(value))
return CRLF_TEXT;
@@ -224,26 +421,70 @@ static int git_path_check_crlf(const char *path, struct git_attr_check *check)
return CRLF_GUESS;
}
+static struct convert_driver *git_path_check_convert(const char *path,
+ struct git_attr_check *check)
+{
+ const char *value = check[1].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;
+}
+
char *convert_to_git(const char *path, const char *src, unsigned long *sizep)
{
- struct git_attr_check check[1];
+ struct git_attr_check check[2];
int crlf = CRLF_GUESS;
+ char *filter = NULL;
+ char *buf, *buf2;
setup_convert_check(check);
- if (!git_checkattr(path, 1, check)) {
+ if (!git_checkattr(path, 2, check)) {
+ struct convert_driver *drv;
crlf = git_path_check_crlf(path, check);
+ drv = git_path_check_convert(path, check);
+ 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;
+ }
+
+ return buf;
}
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[2];
int crlf = CRLF_GUESS;
+ char *filter = NULL;
+ char *buf, *buf2;
setup_convert_check(check);
- if (!git_checkattr(path, 1, check)) {
+ if (!git_checkattr(path, 2, check)) {
+ struct convert_driver *drv;
crlf = git_path_check_crlf(path, check);
+ drv = git_path_check_convert(path, check);
+ if (drv && drv->smudge)
+ filter = drv->smudge;
}
- return crlf_to_worktree(path, src, sizep, crlf);
+
+ buf = crlf_to_worktree(path, src, sizep, crlf);
+
+ buf2 = apply_filter(path, buf ? buf : src, sizep, filter);
+ if (buf2) {
+ free(buf);
+ buf = buf2;
+ }
+
+ return buf;
}
diff --git a/t/t0021-filter.sh b/t/t0021-filter.sh
new file mode 100755
index 0000000..d6bb1c6
--- /dev/null
+++ b/t/t0021-filter.sh
@@ -0,0 +1,36 @@
+#!/bin/sh
+
+test_description='external filter conversion'
+
+. ./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" >.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
+ } >test &&
+ cat test >test.t &&
+ cat test >test.o &&
+ git add test test.t &&
+ rm -f test test.t &&
+ git checkout -- test test.t
+'
+
+test_expect_success check '
+
+ cmp test.o test &&
+ cmp test.o test.t
+
+'
+
+test_done
--
1.5.1.2.919.g280f4
-
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