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[PATCH 01/40] Add initial external odb support

From
Christian Couder <christian.couder@gmail.com>
Date
Jan 3, 2018, 16:33 UTC
Message-ID
<20180103163403.11303-2-chriscool@tuxfamily.org>
In-Reply-To
<20180103163403.11303-1-chriscool@tuxfamily.org>

The external-odb.{c,h} files will contain the functions that are called by the rest of Git mostly from "sha1_file.c" to access the objects managed by the external odbs.

The odb-helper.{c,h} files will contain the functions to actually implement communication with either the internal functions or the external scripts or processes that will manage and provide external git objects.

For now only infrastructure to create helpers from the config and to manage a cache for the 'have' command is implemented.

Helped-by: Jeff King <peff@peff.net>
Signed-off-by: Christian Couder <chriscool@tuxfamily.org>
---
 Makefile       |  2 ++
 cache.h        |  1 +
 external-odb.c | 72 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 external-odb.h |  7 ++++++
 odb-helper.c   | 54 +++++++++++++++++++++++++++++++++++++++++++
 odb-helper.h   | 24 ++++++++++++++++++++
 sha1_file.c    | 19 +++++++++++++++-
 7 files changed, 178 insertions(+), 1 deletion(-)
 create mode 100644 external-odb.c
 create mode 100644 external-odb.h
 create mode 100644 odb-helper.c
 create mode 100644 odb-helper.h
diff --git a/Makefile b/Makefile
index 2a81ae22e9..07694185c9 100644
--- a/Makefile
+++ b/Makefile
@@ -799,6 +799,7 @@ LIB_OBJS += ewah/ewah_bitmap.o
 LIB_OBJS += ewah/ewah_io.o
 LIB_OBJS += ewah/ewah_rlw.o
 LIB_OBJS += exec_cmd.o
+LIB_OBJS += external-odb.o
 LIB_OBJS += fetch-pack.o
 LIB_OBJS += fsck.o
 LIB_OBJS += fsmonitor.o
@@ -834,6 +835,7 @@ LIB_OBJS += notes-cache.o
 LIB_OBJS += notes-merge.o
 LIB_OBJS += notes-utils.o
 LIB_OBJS += object.o
+LIB_OBJS += odb-helper.o
 LIB_OBJS += oidmap.o
 LIB_OBJS += oidset.o
 LIB_OBJS += packfile.o
diff --git a/cache.h b/cache.h
index a2ec8c0b55..21af6442af 100644
--- a/cache.h
+++ b/cache.h
@@ -1587,6 +1587,7 @@ extern void prepare_alt_odb(void);
 extern char *compute_alternate_path(const char *path, struct strbuf *err);
 typedef int alt_odb_fn(struct alternate_object_database *, void *);
 extern int foreach_alt_odb(alt_odb_fn, void*);
+extern void prepare_external_alt_odb(void);
 
 /*
  * Allocate a "struct alternate_object_database" but do _not_ actually
diff --git a/external-odb.c b/external-odb.c
new file mode 100644
index 0000000000..f3ea491333
--- /dev/null
+++ b/external-odb.c
@@ -0,0 +1,72 @@
+#include "cache.h"
+#include "external-odb.h"
+#include "odb-helper.h"
+#include "config.h"
+
+static struct odb_helper *helpers;
+static struct odb_helper **helpers_tail = &helpers;
+
+static struct odb_helper *find_or_create_helper(const char *name, int len)
+{
+	struct odb_helper *o;
+
+	for (o = helpers; o; o = o->next)
+		if (!strncmp(o->name, name, len) && !o->name[len])
+			return o;
+
+	o = odb_helper_new(name, len);
+	*helpers_tail = o;
+	helpers_tail = &o->next;
+
+	return o;
+}
+
+static int external_odb_config(const char *var, const char *value, void *data)
+{
+	struct odb_helper *o;
+	const char *name;
+	int namelen;
+	const char *subkey;
+
+	if (parse_config_key(var, "odb", &name, &namelen, &subkey) < 0)
+		return 0;
+
+	o = find_or_create_helper(name, namelen);
+
+	if (!strcmp(subkey, "promisorremote"))
+		return git_config_string(&o->dealer, var, value);
+
+	return 0;
+}
+
+static void external_odb_init(void)
+{
+	static int initialized;
+
+	if (initialized)
+		return;
+	initialized = 1;
+
+	git_config(external_odb_config, NULL);
+}
+
+const char *external_odb_root(void)
+{
+	static const char *root;
+	if (!root)
+		root = git_pathdup("objects/external");
+	return root;
+}
+
+int external_odb_has_object(const unsigned char *sha1)
+{
+	struct odb_helper *o;
+
+	external_odb_init();
+
+	for (o = helpers; o; o = o->next)
+		if (odb_helper_has_object(o, sha1))
+			return 1;
+	return 0;
+}
+
diff --git a/external-odb.h b/external-odb.h
new file mode 100644
index 0000000000..ae2b228792
--- /dev/null
+++ b/external-odb.h
@@ -0,0 +1,7 @@
+#ifndef EXTERNAL_ODB_H
+#define EXTERNAL_ODB_H
+
+extern const char *external_odb_root(void);
+extern int external_odb_has_object(const unsigned char *sha1);
+
+#endif /* EXTERNAL_ODB_H */
diff --git a/odb-helper.c b/odb-helper.c
new file mode 100644
index 0000000000..1404393807
--- /dev/null
+++ b/odb-helper.c
@@ -0,0 +1,54 @@
+#include "cache.h"
+#include "object.h"
+#include "argv-array.h"
+#include "odb-helper.h"
+#include "run-command.h"
+#include "sha1-lookup.h"
+
+struct odb_helper *odb_helper_new(const char *name, int namelen)
+{
+	struct odb_helper *o;
+
+	o = xcalloc(1, sizeof(*o));
+	o->name = xmemdupz(name, namelen);
+
+	return o;
+}
+
+struct odb_helper_cmd {
+	struct argv_array argv;
+	struct child_process child;
+};
+
+static void odb_helper_load_have(struct odb_helper *o)
+{
+	if (o->have_valid)
+		return;
+	o->have_valid = 1;
+
+	/* TODO */
+}
+
+static const unsigned char *have_sha1_access(size_t index, void *table)
+{
+	struct odb_helper_object *have = table;
+	return have[index].sha1;
+}
+
+static struct odb_helper_object *odb_helper_lookup(struct odb_helper *o,
+						   const unsigned char *sha1)
+{
+	int idx;
+
+	odb_helper_load_have(o);
+	idx = sha1_pos(sha1, o->have, o->have_nr, have_sha1_access);
+	if (idx < 0)
+		return NULL;
+	return &o->have[idx];
+}
+
+int odb_helper_has_object(struct odb_helper *o, const unsigned char *sha1)
+{
+	return !!odb_helper_lookup(o, sha1);
+}
+
diff --git a/odb-helper.h b/odb-helper.h
new file mode 100644
index 0000000000..9395e606ce
--- /dev/null
+++ b/odb-helper.h
@@ -0,0 +1,24 @@
+#ifndef ODB_HELPER_H
+#define ODB_HELPER_H
+
+struct odb_helper {
+	const char *name;
+	const char *dealer;
+
+	struct odb_helper_object {
+		unsigned char sha1[20];
+		unsigned long size;
+		enum object_type type;
+	} *have;
+	int have_nr;
+	int have_alloc;
+	int have_valid;
+
+	struct odb_helper *next;
+};
+
+extern struct odb_helper *odb_helper_new(const char *name, int namelen);
+extern int odb_helper_has_object(struct odb_helper *o,
+				 const unsigned char *sha1);
+
+#endif /* ODB_HELPER_H */
diff --git a/sha1_file.c b/sha1_file.c
index 3da70ac650..3f5ff274e2 100644
--- a/sha1_file.c
+++ b/sha1_file.c
@@ -29,6 +29,7 @@
 #include "mergesort.h"
 #include "quote.h"
 #include "packfile.h"
+#include "external-odb.h"
 
 const unsigned char null_sha1[GIT_MAX_RAWSZ];
 const struct object_id null_oid;
@@ -669,6 +670,21 @@ int foreach_alt_odb(alt_odb_fn fn, void *cb)
 	return r;
 }
 
+void prepare_external_alt_odb(void)
+{
+	static int linked_external;
+	const char *path;
+
+	if (linked_external)
+		return;
+
+	path = external_odb_root();
+	if (!access(path, F_OK)) {
+		link_alt_odb_entry(path, NULL, 0, "");
+		linked_external = 1;
+	}
+}
+
 void prepare_alt_odb(void)
 {
 	const char *alt;
@@ -682,6 +698,7 @@ void prepare_alt_odb(void)
 	link_alt_odb_entries(alt, PATH_SEP, NULL, 0);
 
 	read_info_alternates(get_object_directory(), 0);
+	prepare_external_alt_odb();
 }
 
 /* Returns 1 if we have successfully freshened the file, 0 otherwise. */
@@ -722,7 +739,7 @@ static int check_and_freshen_nonlocal(const unsigned char *sha1, int freshen)
 		if (check_and_freshen_file(path, freshen))
 			return 1;
 	}
-	return 0;
+	return external_odb_has_object(sha1);
 }
 
 static int check_and_freshen(const unsigned char *sha1, int freshen)

-- 
2.16.0.rc0.16.g82191dbc6c.dirty
Previous: Christian CouderNext: Jeff Hostetler
Message 47 of 51 in “Promisor remotes and external ODB support”
  1. 00/40 Promisor remotes and external ODB supportChristian Couder, Jan 3, 2018
  2. 08/40 index-pack: refactor writing of .keep filesChristian Couder, Jan 3, 2018
  3. 12/40 rev-list: support termination at promisor objectsChristian Couder, Jan 3, 2018
  4. 11/40 sha1_file: support lazily fetching missing objectsChristian Couder, Jan 3, 2018
  5. 09/40 introduce fetch-object: fetch one promisor objectChristian Couder, Jan 3, 2018
  6. 18/40 t0400: add 'put_raw_obj' instruction to odb-helper scriptChristian Couder, Jan 3, 2018
  7. 21/40 t0400: add test for external odb write supportChristian Couder, Jan 3, 2018
  8. 24/40 lib-httpd: add upload.shChristian Couder, Jan 3, 2018
  9. 25/40 lib-httpd: add list.shChristian Couder, Jan 3, 2018
  10. 23/40 lib-httpd: pass config file to start_httpd()Christian Couder, Jan 3, 2018
  11. 27/40 odb-helper: add odb_helper_get_raw_object()Christian Couder, Jan 3, 2018
  12. 29/40 Add t0420 to test transfer to HTTP external odbChristian Couder, Jan 3, 2018
  13. 26/40 lib-httpd: add apache-e-odb.confChristian Couder, Jan 3, 2018
  14. 28/40 pack-objects: don't pack objects in external odbsChristian Couder, Jan 3, 2018
  15. Jeff HostetlerJan 4, 2018
  16. Christian CouderMar 19, 2018
  17. 30/40 external-odb: add 'get_direct' supportChristian Couder, Jan 3, 2018
  18. 31/40 odb-helper: add 'script_mode' to 'struct odb_helper'Christian Couder, Jan 3, 2018
  19. 32/40 odb-helper: add init_object_process()Christian Couder, Jan 3, 2018
  20. 34/40 Add t0460 to test passing git objectsChristian Couder, Jan 3, 2018
  21. 33/40 Add t0450 to test 'get_direct' mechanismChristian Couder, Jan 3, 2018
  22. 40/40 Add Documentation/technical/external-odb.txtChristian Couder, Jan 3, 2018
  23. 35/40 odb-helper: add put_object_process()Christian Couder, Jan 3, 2018
  24. 36/40 Add t0470 to test passing raw objectsChristian Couder, Jan 3, 2018
  25. 37/40 odb-helper: add have_object_process()Christian Couder, Jan 3, 2018
  26. 38/40 Add t0480 to test "have" capability and raw objectsChristian Couder, Jan 3, 2018
  27. 39/40 external-odb: use 'odb=magic' attribute to mark odb blobsChristian Couder, Jan 3, 2018
  28. 10/40 external-odb: implement external_odb_get_directChristian Couder, Jan 3, 2018
  29. Jeff HostetlerJan 4, 2018
  30. Christian CouderJan 15, 2018
  31. 22/40 Add t0410 to test external ODB transferChristian Couder, Jan 3, 2018
  32. 20/40 external-odb: accept only blobs for nowChristian Couder, Jan 3, 2018
  33. 19/40 external odb: add 'put_raw_obj' supportChristian Couder, Jan 3, 2018
  34. 13/40 gc: do not repack promisor packfilesChristian Couder, Jan 3, 2018
  35. 16/40 odb-helper: add 'enum odb_helper_type'Christian Couder, Jan 3, 2018
  36. 17/40 odb-helper: add odb_helper_init() to send 'init' instructionChristian Couder, Jan 3, 2018
  37. 14/40 sha1_file: prepare for external odbsChristian Couder, Jan 3, 2018
  38. Jeff HostetlerJan 4, 2018
  39. Christian CouderJan 16, 2018
  40. 07/40 fsck: support promisor objects as CLI argumentChristian Couder, Jan 3, 2018
  41. 15/40 external-odb: add script mode supportChristian Couder, Jan 3, 2018
  42. Jeff HostetlerJan 4, 2018
  43. Christian CouderMar 19, 2018
  44. 06/40 fsck: support referenced promisor objectsChristian Couder, Jan 3, 2018
  45. 05/40 fsck: support refs pointing to promisor objectsChristian Couder, Jan 3, 2018
  46. 02/40 Add GIT_NO_EXTERNAL_ODB env variableChristian Couder, Jan 3, 2018
  47. 01/40 Add initial external odb supportChristian Couder, Jan 3, 2018
  48. Jeff HostetlerJan 4, 2018
  49. Christian CouderJan 15, 2018
  50. 03/40 external-odb: add has_external_odb()Christian Couder, Jan 3, 2018
  51. 04/40 fsck: introduce promisor objectsChristian Couder, Jan 3, 2018

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