convert: add [async_]convert_to_working_tree_ca() variants

Separate the attribute gathering from the actual conversion by adding
_ca() variants of the conversion functions. These variants receive a
precomputed 'struct conv_attrs', not relying, thus, on an index state.
They will be used in a future patch adding parallel checkout support,
for two reasons:

- We will already load the conversion attributes in checkout_entry(),
  before conversion, to decide whether a path is eligible for parallel
  checkout. Therefore, it would be wasteful to load them again later,
  for the actual conversion.

- The parallel workers will be responsible for reading, converting and
  writing blobs to the working tree. They won't have access to the main
  process' index state, so they cannot load the attributes. Instead,
  they will receive the preloaded ones and call the _ca() variant of
  the conversion functions. Furthermore, the attributes machinery is
  optimized to handle paths in sequential order, so it's better to leave
  it for the main process, anyway.

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Signed-off-by: Matheus Tavares <matheus.bernardino@usp.br>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

2 files changed, 60 insertions, 37 deletions

diff --git a/convert.c b/convert.c
index f13b001273..0307374241 100644
--- a/convert.c
+++ b/convert.c
@@ -1447,19 +1447,16 @@ void convert_to_git_filter_fd(const struct index_state *istate,
 	ident_to_git(dst->buf, dst->len, dst, ca.ident);
 }
 
-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,
-					    const struct checkout_metadata *meta,
-					    struct delayed_checkout *dco)
+static int convert_to_working_tree_ca_internal(const struct conv_attrs *ca,
+					       const char *path, const char *src,
+					       size_t len, struct strbuf *dst,
+					       int normalizing,
+					       const struct checkout_metadata *meta,
+					       struct delayed_checkout *dco)
 {
 	int ret = 0, ret_filter = 0;
-	struct conv_attrs ca;
-
-	convert_attrs(istate, &ca, path);
 
-	ret |= ident_to_worktree(src, len, dst, ca.ident);
+	ret |= ident_to_worktree(src, len, dst, ca->ident);
 	if (ret) {
 		src = dst->buf;
 		len = dst->len;
@@ -1469,49 +1466,56 @@ static int convert_to_working_tree_internal(const struct index_state *istate,
 	 * is a smudge or process filter (even if the process filter doesn't
 	 * support smudge).  The filters might expect CRLFs.
 	 */
-	if ((ca.drv && (ca.drv->smudge || ca.drv->process)) || !normalizing) {
-		ret |= crlf_to_worktree(src, len, dst, ca.crlf_action);
+	if ((ca->drv && (ca->drv->smudge || ca->drv->process)) || !normalizing) {
+		ret |= crlf_to_worktree(src, len, dst, ca->crlf_action);
 		if (ret) {
 			src = dst->buf;
 			len = dst->len;
 		}
 	}
 
-	ret |= encode_to_worktree(path, src, len, dst, ca.working_tree_encoding);
+	ret |= encode_to_worktree(path, src, len, dst, ca->working_tree_encoding);
 	if (ret) {
 		src = dst->buf;
 		len = dst->len;
 	}
 
 	ret_filter = apply_filter(
-		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);
+		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);
 
 	return ret | ret_filter;
 }
 
-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_convert_to_working_tree_ca(const struct conv_attrs *ca,
+				     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, meta, dco);
+	return convert_to_working_tree_ca_internal(ca, 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,
-			    const struct checkout_metadata *meta)
+int convert_to_working_tree_ca(const struct conv_attrs *ca,
+			       const char *path, const char *src,
+			       size_t len, struct strbuf *dst,
+			       const struct checkout_metadata *meta)
 {
-	return convert_to_working_tree_internal(istate, path, src, len, dst, 0, meta, NULL);
+	return convert_to_working_tree_ca_internal(ca, 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, NULL);
+	struct conv_attrs ca;
+	int ret;
+
+	convert_attrs(istate, &ca, path);
+	ret = convert_to_working_tree_ca_internal(&ca, path, src, len, dst, 1,
+						  NULL, NULL);
 	if (ret) {
 		src = dst->buf;
 		len = dst->len;
diff --git a/convert.h b/convert.h
index 5678e99922..a4838b5e5c 100644
--- a/convert.h
+++ b/convert.h
@@ -99,15 +99,34 @@ const char *get_convert_attr_ascii(const struct index_state *istate,
 int convert_to_git(const struct index_state *istate,
 		   const char *path, const char *src, size_t len,
 		   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,
-			    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 convert_to_working_tree_ca(const struct conv_attrs *ca,
+			       const char *path, const char *src,
+			       size_t len, struct strbuf *dst,
+			       const struct checkout_metadata *meta);
+int async_convert_to_working_tree_ca(const struct conv_attrs *ca,
+				     const char *path, const char *src,
+				     size_t len, struct strbuf *dst,
+				     const struct checkout_metadata *meta,
+				     void *dco);
+static inline int 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)
+{
+	struct conv_attrs ca;
+	convert_attrs(istate, &ca, path);
+	return convert_to_working_tree_ca(&ca, path, src, len, dst, meta);
+}
+static inline 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)
+{
+	struct conv_attrs ca;
+	convert_attrs(istate, &ca, path);
+	return async_convert_to_working_tree_ca(&ca, path, src, len, dst, meta, dco);
+}
 int async_query_available_blobs(const char *cmd,
 				struct string_list *available_paths);
 int renormalize_buffer(const struct index_state *istate,