convert: permit passing additional metadata to filter processes

There are a variety of situations where a filter process can make use of
some additional metadata.  For example, some people find the ident
filter too limiting and would like to include the commit or the branch
in their smudged files.  This information isn't available during
checkout as HEAD hasn't been updated at that point, and it wouldn't be
available in archives either.

Let's add a way to pass this metadata down to the filter.  We pass the
blob we're operating on, the treeish (preferring the commit over the
tree if one exists), and the ref we're operating on.  Note that we won't
pass this information in all cases, such as when renormalizing or when
we're performing diffs, since it doesn't make sense in those cases.

The data we currently get from the filter process looks like the
following:

  command=smudge
  pathname=git.c
  0000

With this change, we'll get data more like this:

  command=smudge
  pathname=git.c
  refname=refs/tags/v2.25.1
  treeish=c522f061d551c9bb8684a7c3859b2ece4499b56b
  blob=7be7ad34bd053884ec48923706e70c81719a8660
  0000

There are a couple things to note about this approach.  For operations
like checkout, treeish will always be a commit, since we cannot check
out individual trees, but for other operations, like archive, we can end
up operating on only a particular tree, so we'll provide only a tree as
the treeish.  Similar comments apply for refname, since there are a
variety of cases in which we won't have a ref.

This commit wires up the code to print this information, but doesn't
pass any of it at this point.  In a future commit, we'll have various
code paths pass the actual useful data down.

Signed-off-by: brian m. carlson <bk2204@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/apply.c b/apply.c
index bdc008fae2ad77197a859d64196bf91161cf8d67..144c19aaca80d943e237ffd84f215a49415e0d5a 100644 (file)
--- a/apply.c
+++ b/apply.c
@@ -4349,7 +4349,7 @@ static int try_create_file(struct apply_state *state, const char *path,
        if (fd < 0)
                return 1;
 
-       if (convert_to_working_tree(state->repo->index, path, buf, size, &nbuf)) {
+       if (convert_to_working_tree(state->repo->index, path, buf, size, &nbuf, NULL)) {
                size = nbuf.len;
                buf  = nbuf.buf;
        }

diff --git a/archive.c b/archive.c
index a8da0fcc4f0cc47e585b3b378109fbd84496ed15..d9e92cce582b6d5fce8869752618b2c9ecff7271 100644 (file)
--- a/archive.c
+++ b/archive.c
@@ -85,7 +85,7 @@ void *object_file_to_archive(const struct archiver_args *args,
                size_t size = 0;
 
                strbuf_attach(&buf, buffer, *sizep, *sizep + 1);
-               convert_to_working_tree(args->repo->index, path, buf.buf, buf.len, &buf);
+               convert_to_working_tree(args->repo->index, path, buf.buf, buf.len, &buf, NULL);
                if (commit)
                        format_subst(commit, buf.buf, buf.len, &buf);
                buffer = strbuf_detach(&buf, &size);

diff --git a/builtin/cat-file.c b/builtin/cat-file.c
index 272f9fc6d7cb540c89c3dca13969398afd3c1ee1..545fed4924a6d47f0fed64f3d7967f4decc5797e 100644 (file)
--- a/builtin/cat-file.c
+++ b/builtin/cat-file.c
@@ -42,7 +42,7 @@ static int filter_object(const char *path, unsigned mode,
                             oid_to_hex(oid), path);
        if ((type == OBJ_BLOB) && S_ISREG(mode)) {
                struct strbuf strbuf = STRBUF_INIT;
-               if (convert_to_working_tree(&the_index, path, *buf, *size, &strbuf)) {
+               if (convert_to_working_tree(&the_index, path, *buf, *size, &strbuf, NULL)) {
                        free(*buf);
                        *size = strbuf.len;
                        *buf = strbuf_detach(&strbuf, NULL);

diff --git a/convert.c b/convert.c
index 5ead3ce678bb746fa82cef9e3b8e8ac407aa0741..6261921cfb7728e23f78bb7d340583b52300d638 100644 (file)
--- a/convert.c
+++ b/convert.c
@@ -797,6 +797,7 @@ static void handle_filter_error(const struct strbuf *filter_status,
 static int apply_multi_file_filter(const char *path, const char *src, size_t len,
                                   int fd, struct strbuf *dst, const char *cmd,
                                   const unsigned int wanted_capability,
+                                  const struct checkout_metadata *meta,
                                   struct delayed_checkout *dco)
 {
        int err;
@@ -855,6 +856,24 @@ static int apply_multi_file_filter(const char *path, const char *src, size_t len
        if (err)
                goto done;
 
+       if (meta && meta->refname) {
+               err = packet_write_fmt_gently(process->in, "ref=%s\n", meta->refname);
+               if (err)
+                       goto done;
+       }
+
+       if (meta && !is_null_oid(&meta->treeish)) {
+               err = packet_write_fmt_gently(process->in, "treeish=%s\n", oid_to_hex(&meta->treeish));
+               if (err)
+                       goto done;
+       }
+
+       if (meta && !is_null_oid(&meta->blob)) {
+               err = packet_write_fmt_gently(process->in, "blob=%s\n", oid_to_hex(&meta->blob));
+               if (err)
+                       goto done;
+       }
+
        if ((entry->supported_capabilities & CAP_DELAY) &&
            dco && dco->state == CE_CAN_DELAY) {
                can_delay = 1;
@@ -971,6 +990,7 @@ static struct convert_driver {
 static int apply_filter(const char *path, const char *src, size_t len,
                        int fd, struct strbuf *dst, struct convert_driver *drv,
                        const unsigned int wanted_capability,
+                       const struct checkout_metadata *meta,
                        struct delayed_checkout *dco)
 {
        const char *cmd = NULL;
@@ -990,7 +1010,7 @@ static int apply_filter(const char *path, const char *src, size_t len,
                return apply_single_file_filter(path, src, len, fd, dst, cmd);
        else if (drv->process && *drv->process)
                return apply_multi_file_filter(path, src, len, fd, dst,
-                       drv->process, wanted_capability, dco);
+                       drv->process, wanted_capability, meta, dco);
 
        return 0;
 }
@@ -1368,7 +1388,7 @@ int would_convert_to_git_filter_fd(const struct index_state *istate, const char
        if (!ca.drv->required)
                return 0;
 
-       return apply_filter(path, NULL, 0, -1, NULL, ca.drv, CAP_CLEAN, NULL);
+       return apply_filter(path, NULL, 0, -1, NULL, ca.drv, CAP_CLEAN, NULL, NULL);
 }
 
 const char *get_convert_attr_ascii(const struct index_state *istate, const char *path)
@@ -1406,7 +1426,7 @@ int convert_to_git(const struct index_state *istate,
 
        convert_attrs(istate, &ca, path);
 
-       ret |= apply_filter(path, src, len, -1, dst, ca.drv, CAP_CLEAN, NULL);
+       ret |= apply_filter(path, src, len, -1, dst, ca.drv, CAP_CLEAN, NULL, NULL);
        if (!ret && ca.drv && ca.drv->required)
                die(_("%s: clean filter '%s' failed"), path, ca.drv->name);
 
@@ -1441,7 +1461,7 @@ void convert_to_git_filter_fd(const struct index_state *istate,
        assert(ca.drv);
        assert(ca.drv->clean || ca.drv->process);
 
-       if (!apply_filter(path, NULL, 0, fd, dst, ca.drv, CAP_CLEAN, NULL))
+       if (!apply_filter(path, NULL, 0, fd, dst, ca.drv, CAP_CLEAN, NULL, NULL))
                die(_("%s: clean filter '%s' failed"), path, ca.drv->name);
 
        encode_to_git(path, dst->buf, dst->len, dst, ca.working_tree_encoding, conv_flags);
@@ -1452,7 +1472,9 @@ void convert_to_git_filter_fd(const struct index_state *istate,
 static int convert_to_working_tree_internal(const struct index_state *istate,
                                            const char *path, const char *src,
                                            size_t len, struct strbuf *dst,
-                                           int normalizing, struct delayed_checkout *dco)
+                                           int normalizing,
+                                           const struct checkout_metadata *meta,
+                                           struct delayed_checkout *dco)
 {
        int ret = 0, ret_filter = 0;
        struct conv_attrs ca;
@@ -1484,7 +1506,7 @@ static int convert_to_working_tree_internal(const struct index_state *istate,
        }
 
        ret_filter = apply_filter(
-               path, src, len, -1, dst, ca.drv, CAP_SMUDGE, dco);
+               path, src, len, -1, dst, ca.drv, CAP_SMUDGE, meta, dco);
        if (!ret_filter && ca.drv && ca.drv->required)
                die(_("%s: smudge filter %s failed"), path, ca.drv->name);
 
@@ -1494,22 +1516,24 @@ static int convert_to_working_tree_internal(const struct index_state *istate,
 int async_convert_to_working_tree(const struct index_state *istate,
                                  const char *path, const char *src,
                                  size_t len, struct strbuf *dst,
+                                 const struct checkout_metadata *meta,
                                  void *dco)
 {
-       return convert_to_working_tree_internal(istate, path, src, len, dst, 0, dco);
+       return convert_to_working_tree_internal(istate, path, src, len, dst, 0, meta, dco);
 }
 
 int convert_to_working_tree(const struct index_state *istate,
                            const char *path, const char *src,
-                           size_t len, struct strbuf *dst)
+                           size_t len, struct strbuf *dst,
+                           const struct checkout_metadata *meta)
 {
-       return convert_to_working_tree_internal(istate, path, src, len, dst, 0, NULL);
+       return convert_to_working_tree_internal(istate, path, src, len, dst, 0, meta, NULL);
 }
 
 int renormalize_buffer(const struct index_state *istate, const char *path,
                       const char *src, size_t len, struct strbuf *dst)
 {
-       int ret = convert_to_working_tree_internal(istate, path, src, len, dst, 1, NULL);
+       int ret = convert_to_working_tree_internal(istate, path, src, len, dst, 1, NULL, NULL);
        if (ret) {
                src = dst->buf;
                len = dst->len;

diff --git a/convert.h b/convert.h
index 3710969d43d6a16c6eab2e8302f962aa466ccd9f..894e01c38b896f193c320d701ad0e5923c2226a8 100644 (file)
--- a/convert.h
+++ b/convert.h
@@ -4,10 +4,10 @@
 #ifndef CONVERT_H
 #define CONVERT_H
 
+#include "hash.h"
 #include "string-list.h"
 
 struct index_state;
-struct object_id;
 struct strbuf;
 
 #define CONV_EOL_RNDTRP_DIE   (1<<0) /* Die if CRLF to LF to CRLF is different */
@@ -57,6 +57,12 @@ struct delayed_checkout {
        struct string_list paths;
 };
 
+struct checkout_metadata {
+       const char *refname;
+       struct object_id treeish;
+       struct object_id blob;
+};
+
 extern enum eol core_eol;
 extern char *check_roundtrip_encoding;
 const char *get_cached_convert_stats_ascii(const struct index_state *istate,
@@ -71,10 +77,12 @@ int convert_to_git(const struct index_state *istate,
                   struct strbuf *dst, int conv_flags);
 int convert_to_working_tree(const struct index_state *istate,
                            const char *path, const char *src,
-                           size_t len, struct strbuf *dst);
+                           size_t len, struct strbuf *dst,
+                           const struct checkout_metadata *meta);
 int async_convert_to_working_tree(const struct index_state *istate,
                                  const char *path, const char *src,
                                  size_t len, struct strbuf *dst,
+                                 const struct checkout_metadata *meta,
                                  void *dco);
 int async_query_available_blobs(const char *cmd,
                                struct string_list *available_paths);

diff --git a/diff.c b/diff.c
index f2cfbf2214a29fc9ddf0e356230df7625d3d1139..12761c8017ca83ffc0b77420b61989199ceb02a6 100644 (file)
--- a/diff.c
+++ b/diff.c
@@ -4071,7 +4071,7 @@ static void prep_temp_blob(struct index_state *istate,
        if (!temp->tempfile)
                die_errno("unable to create temp-file");
        if (convert_to_working_tree(istate, path,
-                       (const char *)blob, (size_t)size, &buf)) {
+                       (const char *)blob, (size_t)size, &buf, NULL)) {
                blob = buf.buf;
                size = buf.len;
        }

diff --git a/entry.c b/entry.c
index 53380bb614c19e82edfb45049f1703b4a3b9c8a3..4b2d9b2dadb99ef5084c34ccb9fd393fec0978e6 100644 (file)
--- a/entry.c
+++ b/entry.c
@@ -315,13 +315,13 @@ static int write_entry(struct cache_entry *ce,
                 */
                if (dco && dco->state != CE_NO_DELAY) {
                        ret = async_convert_to_working_tree(state->istate, ce->name, new_blob,
-                                                           size, &buf, dco);
+                                                           size, &buf, NULL, dco);
                        if (ret && string_list_has_string(&dco->paths, ce->name)) {
                                free(new_blob);
                                goto delayed;
                        }
                } else
-                       ret = convert_to_working_tree(state->istate, ce->name, new_blob, size, &buf);
+                       ret = convert_to_working_tree(state->istate, ce->name, new_blob, size, &buf, NULL);
 
                if (ret) {
                        free(new_blob);

diff --git a/merge-recursive.c b/merge-recursive.c
index 7a4e6f20fa8c8b163239d2872795e4d51a3d9b34..d92e2acf1ed2cfb4d4ce1e50fee3a64fb70b91ac 100644 (file)
--- a/merge-recursive.c
+++ b/merge-recursive.c
@@ -958,7 +958,7 @@ static int update_file_flags(struct merge_options *opt,
                if (S_ISREG(contents->mode)) {
                        struct strbuf strbuf = STRBUF_INIT;
                        if (convert_to_working_tree(opt->repo->index,
-                                                   path, buf, size, &strbuf)) {
+                                                   path, buf, size, &strbuf, NULL)) {
                                free(buf);
                                size = strbuf.len;
                                buf = strbuf_detach(&strbuf, NULL);