Merge branch 'jk/for-each-object-iteration'

The API to iterate over all objects learned to optionally list
objects in the order they appear in packfiles, which helps locality
of access if the caller accesses these objects while as objects are
enumerated.

* jk/for-each-object-iteration:
  for_each_*_object: move declarations to object-store.h
  cat-file: use a single strbuf for all output
  cat-file: split batch "buf" into two variables
  cat-file: use oidset check-and-insert
  cat-file: support "unordered" output for --batch-all-objects
  cat-file: rename batch_{loose,packed}_object callbacks
  t1006: test cat-file --batch-all-objects with duplicates
  for_each_packed_object: support iterating in pack-order
  for_each_*_object: give more comprehensive docstrings
  for_each_*_object: take flag arguments as enum
  for_each_*_object: store flag definitions in a single location

2 files changed, 82 insertions, 28 deletions

diff --git a/builtin/cat-file.c b/builtin/cat-file.c
index 4a44b2404f..08dced2614 100644
--- a/builtin/cat-file.c
+++ b/builtin/cat-file.c
@@ -21,6 +21,7 @@ struct batch_options {
 	int print_contents;
 	int buffer_output;
 	int all_objects;
+	int unordered;
 	int cmdmode; /* may be 'w' or 'c' for --filters or --textconv */
 	const char *format;
 };
@@ -337,11 +338,11 @@ static void print_object_or_die(struct batch_options *opt, struct expand_data *d
 	}
 }
 
-static void batch_object_write(const char *obj_name, struct batch_options *opt,
+static void batch_object_write(const char *obj_name,
+			       struct strbuf *scratch,
+			       struct batch_options *opt,
 			       struct expand_data *data)
 {
-	struct strbuf buf = STRBUF_INIT;
-
 	if (!data->skip_object_info &&
 	    oid_object_info_extended(the_repository, &data->oid, &data->info,
 				     OBJECT_INFO_LOOKUP_REPLACE) < 0) {
@@ -351,10 +352,10 @@ static void batch_object_write(const char *obj_name, struct batch_options *opt,
 		return;
 	}
 
-	strbuf_expand(&buf, opt->format, expand_format, data);
-	strbuf_addch(&buf, '\n');
-	batch_write(opt, buf.buf, buf.len);
-	strbuf_release(&buf);
+	strbuf_reset(scratch);
+	strbuf_expand(scratch, opt->format, expand_format, data);
+	strbuf_addch(scratch, '\n');
+	batch_write(opt, scratch->buf, scratch->len);
 
 	if (opt->print_contents) {
 		print_object_or_die(opt, data);
@@ -362,7 +363,9 @@ static void batch_object_write(const char *obj_name, struct batch_options *opt,
 	}
 }
 
-static void batch_one_object(const char *obj_name, struct batch_options *opt,
+static void batch_one_object(const char *obj_name,
+			     struct strbuf *scratch,
+			     struct batch_options *opt,
 			     struct expand_data *data)
 {
 	struct object_context ctx;
@@ -404,42 +407,70 @@ static void batch_one_object(const char *obj_name, struct batch_options *opt,
 		return;
 	}
 
-	batch_object_write(obj_name, opt, data);
+	batch_object_write(obj_name, scratch, opt, data);
 }
 
 struct object_cb_data {
 	struct batch_options *opt;
 	struct expand_data *expand;
+	struct oidset *seen;
+	struct strbuf *scratch;
 };
 
 static int batch_object_cb(const struct object_id *oid, void *vdata)
 {
 	struct object_cb_data *data = vdata;
 	oidcpy(&data->expand->oid, oid);
-	batch_object_write(NULL, data->opt, data->expand);
+	batch_object_write(NULL, data->scratch, data->opt, data->expand);
 	return 0;
 }
 
-static int batch_loose_object(const struct object_id *oid,
-			      const char *path,
-			      void *data)
+static int collect_loose_object(const struct object_id *oid,
+				const char *path,
+				void *data)
 {
 	oid_array_append(data, oid);
 	return 0;
 }
 
-static int batch_packed_object(const struct object_id *oid,
-			       struct packed_git *pack,
-			       uint32_t pos,
-			       void *data)
+static int collect_packed_object(const struct object_id *oid,
+				 struct packed_git *pack,
+				 uint32_t pos,
+				 void *data)
 {
 	oid_array_append(data, oid);
 	return 0;
 }
 
+static int batch_unordered_object(const struct object_id *oid, void *vdata)
+{
+	struct object_cb_data *data = vdata;
+
+	if (oidset_insert(data->seen, oid))
+		return 0;
+
+	return batch_object_cb(oid, data);
+}
+
+static int batch_unordered_loose(const struct object_id *oid,
+				 const char *path,
+				 void *data)
+{
+	return batch_unordered_object(oid, data);
+}
+
+static int batch_unordered_packed(const struct object_id *oid,
+				  struct packed_git *pack,
+				  uint32_t pos,
+				  void *data)
+{
+	return batch_unordered_object(oid, data);
+}
+
 static int batch_objects(struct batch_options *opt)
 {
-	struct strbuf buf = STRBUF_INIT;
+	struct strbuf input = STRBUF_INIT;
+	struct strbuf output = STRBUF_INIT;
 	struct expand_data data;
 	int save_warning;
 	int retval = 0;
@@ -454,8 +485,9 @@ static int batch_objects(struct batch_options *opt)
 	 */
 	memset(&data, 0, sizeof(data));
 	data.mark_query = 1;
-	strbuf_expand(&buf, opt->format, expand_format, &data);
+	strbuf_expand(&output, opt->format, expand_format, &data);
 	data.mark_query = 0;
+	strbuf_release(&output);
 	if (opt->cmdmode)
 		data.split_on_whitespace = 1;
 
@@ -473,19 +505,37 @@ static int batch_objects(struct batch_options *opt)
 		data.info.typep = &data.type;
 
 	if (opt->all_objects) {
-		struct oid_array sa = OID_ARRAY_INIT;
 		struct object_cb_data cb;
 
-		for_each_loose_object(batch_loose_object, &sa, 0);
-		for_each_packed_object(batch_packed_object, &sa, 0);
 		if (repository_format_partial_clone)
 			warning("This repository has extensions.partialClone set. Some objects may not be loaded.");
 
 		cb.opt = opt;
 		cb.expand = &data;
-		oid_array_for_each_unique(&sa, batch_object_cb, &cb);
+		cb.scratch = &output;
+
+		if (opt->unordered) {
+			struct oidset seen = OIDSET_INIT;
+
+			cb.seen = &seen;
+
+			for_each_loose_object(batch_unordered_loose, &cb, 0);
+			for_each_packed_object(batch_unordered_packed, &cb,
+					       FOR_EACH_OBJECT_PACK_ORDER);
+
+			oidset_clear(&seen);
+		} else {
+			struct oid_array sa = OID_ARRAY_INIT;
+
+			for_each_loose_object(collect_loose_object, &sa, 0);
+			for_each_packed_object(collect_packed_object, &sa, 0);
+
+			oid_array_for_each_unique(&sa, batch_object_cb, &cb);
+
+			oid_array_clear(&sa);
+		}
 
-		oid_array_clear(&sa);
+		strbuf_release(&output);
 		return 0;
 	}
 
@@ -499,14 +549,14 @@ static int batch_objects(struct batch_options *opt)
 	save_warning = warn_on_object_refname_ambiguity;
 	warn_on_object_refname_ambiguity = 0;
 
-	while (strbuf_getline(&buf, stdin) != EOF) {
+	while (strbuf_getline(&input, stdin) != EOF) {
 		if (data.split_on_whitespace) {
 			/*
 			 * Split at first whitespace, tying off the beginning
 			 * of the string and saving the remainder (or NULL) in
 			 * data.rest.
 			 */
-			char *p = strpbrk(buf.buf, " \t");
+			char *p = strpbrk(input.buf, " \t");
 			if (p) {
 				while (*p && strchr(" \t", *p))
 					*p++ = '\0';
@@ -514,10 +564,11 @@ static int batch_objects(struct batch_options *opt)
 			data.rest = p;
 		}
 
-		batch_one_object(buf.buf, opt, &data);
+		batch_one_object(input.buf, &output, opt, &data);
 	}
 
-	strbuf_release(&buf);
+	strbuf_release(&input);
+	strbuf_release(&output);
 	warn_on_object_refname_ambiguity = save_warning;
 	return retval;
 }
@@ -586,6 +637,8 @@ int cmd_cat_file(int argc, const char **argv, const char *prefix)
 			 N_("follow in-tree symlinks (used with --batch or --batch-check)")),
 		OPT_BOOL(0, "batch-all-objects", &batch.all_objects,
 			 N_("show all objects with --batch or --batch-check")),
+		OPT_BOOL(0, "unordered", &batch.unordered,
+			 N_("do not order --batch-all-objects output")),
 		OPT_END()
 	};
 
diff --git a/builtin/prune-packed.c b/builtin/prune-packed.c
index 4ff525e50f..a9e7b552b9 100644
--- a/builtin/prune-packed.c
+++ b/builtin/prune-packed.c
@@ -3,6 +3,7 @@
 #include "progress.h"
 #include "parse-options.h"
 #include "packfile.h"
+#include "object-store.h"
 
 static const char * const prune_packed_usage[] = {
 	N_("git prune-packed [-n | --dry-run] [-q | --quiet]"),