Merge branch 'ps/reftable-api-revamp' into next

Overhaul of the reftable API.

* ps/reftable-api-revamp:
  reftable/table: move printing logic into test helper
  reftable/constants: make block types part of the public interface
  reftable/table: introduce iterator for table blocks
  reftable/table: add `reftable_table` to the public interface
  reftable/block: expose a generic iterator over reftable records
  reftable/block: make block iterators reseekable
  reftable/block: store block pointer in the block iterator
  reftable/block: create public interface for reading blocks
  git-zlib: use `struct z_stream_s` instead of typedef
  reftable/block: rename `block_reader` to `reftable_block`
  reftable/block: rename `block` to `block_data`
  reftable/table: move reading block into block reader
  reftable/block: simplify how we track restart points
  reftable/blocksource: consolidate code into a single file
  reftable/reader: rename data structure to "table"
  reftable: fix formatting of the license header

Author: gitster

Documentation/howto/recover-corrupted-object-harder.adoc

@@ -125,7 +125,7 @@ static int try_zlib(unsigned char *buf, int len)
 {
 	/* make this absurdly large so we don't have to loop */
 	static unsigned char out[1024*1024];
-	z_stream z;
+	struct z_stream_s z;
 	int ret;
 
 	memset(&z, 0, sizeof(z));
@@ -278,7 +278,7 @@ int main(int argc, char **argv)
 	static unsigned char buf[25 * 1024 * 1024];
 	static unsigned char out[25 * 1024 * 1024];
 	int len;
-	z_stream z;
+	struct z_stream_s z;
 	int ret;
 
 	len = read(0, buf, sizeof(buf));

Makefile

@@ -1377,10 +1377,10 @@ UNIT_TEST_PROGRAMS += t-reftable-basics
 UNIT_TEST_PROGRAMS += t-reftable-block
 UNIT_TEST_PROGRAMS += t-reftable-merged
 UNIT_TEST_PROGRAMS += t-reftable-pq
-UNIT_TEST_PROGRAMS += t-reftable-reader
 UNIT_TEST_PROGRAMS += t-reftable-readwrite
 UNIT_TEST_PROGRAMS += t-reftable-record
 UNIT_TEST_PROGRAMS += t-reftable-stack
+UNIT_TEST_PROGRAMS += t-reftable-table
 UNIT_TEST_PROGS = $(patsubst %,$(UNIT_TEST_BIN)/%$X,$(UNIT_TEST_PROGRAMS))
 UNIT_TEST_OBJS += $(UNIT_TEST_DIR)/test-lib.o
 UNIT_TEST_OBJS += $(UNIT_TEST_DIR)/lib-reftable.o
@@ -2737,10 +2737,10 @@ REFTABLE_OBJS += reftable/blocksource.o
 REFTABLE_OBJS += reftable/iter.o
 REFTABLE_OBJS += reftable/merged.o
 REFTABLE_OBJS += reftable/pq.o
-REFTABLE_OBJS += reftable/reader.o
 REFTABLE_OBJS += reftable/record.o
 REFTABLE_OBJS += reftable/stack.o
 REFTABLE_OBJS += reftable/system.o
+REFTABLE_OBJS += reftable/table.o
 REFTABLE_OBJS += reftable/tree.o
 REFTABLE_OBJS += reftable/writer.o
 

compat/zlib-compat.h

@@ -4,8 +4,8 @@
 #ifdef HAVE_ZLIB_NG
 # include <zlib-ng.h>
 
-# define z_stream zng_stream
-#define gz_header_s zng_gz_header_s
+# define z_stream_s zng_stream_s
+# define gz_header_s zng_gz_header_s
 
 # define crc32(crc, buf, len) zng_crc32(crc, buf, len)
 

git-zlib.h

@@ -4,7 +4,7 @@
 #include "compat/zlib-compat.h"
 
 typedef struct git_zstream {
-	z_stream z;
+	struct z_stream_s z;
 	unsigned long avail_in;
 	unsigned long avail_out;
 	unsigned long total_in;

meson.build

@@ -446,10 +446,10 @@ libgit_sources = [
   'reftable/iter.c',
   'reftable/merged.c',
   'reftable/pq.c',
-  'reftable/reader.c',
   'reftable/record.c',
   'reftable/stack.c',
   'reftable/system.c',
+  'reftable/table.c',
   'reftable/tree.c',
   'reftable/writer.c',
   'remote.c',

reftable/basics.c

@@ -1,10 +1,10 @@
 /*
-Copyright 2020 Google LLC
-
-Use of this source code is governed by a BSD-style
-license that can be found in the LICENSE file or at
-https://developers.google.com/open-source/licenses/bsd
-*/
+ * Copyright 2020 Google LLC
+ *
+ * Use of this source code is governed by a BSD-style
+ * license that can be found in the LICENSE file or at
+ * https://developers.google.com/open-source/licenses/bsd
+ */
 
 #define REFTABLE_ALLOW_BANNED_ALLOCATORS
 #include "basics.h"

reftable/basics.h

@@ -1,10 +1,10 @@
 /*
-Copyright 2020 Google LLC
-
-Use of this source code is governed by a BSD-style
-license that can be found in the LICENSE file or at
-https://developers.google.com/open-source/licenses/bsd
-*/
+ * Copyright 2020 Google LLC
+ *
+ * Use of this source code is governed by a BSD-style
+ * license that can be found in the LICENSE file or at
+ * https://developers.google.com/open-source/licenses/bsd
+ */
 
 #ifndef BASICS_H
 #define BASICS_H
@@ -18,13 +18,6 @@ license that can be found in the LICENSE file or at
 
 #define REFTABLE_UNUSED __attribute__((__unused__))
 
-struct reftable_buf {
-	size_t alloc;
-	size_t len;
-	char *buf;
-};
-#define REFTABLE_BUF_INIT { 0 }
-
 /*
  * Initialize the buffer such that it is ready for use. This is equivalent to
  * using REFTABLE_BUF_INIT for stack-allocated variables.