reftable: add dump utility

provide a command-line utility for inspecting individual tables, and
inspecting a complete ref database

Signed-off-by: Han-Wen Nienhuys <hanwen@google.com>
Helped-by: Carlo Marcelo Arenas Belón <carenas@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/reftable/dump.c b/reftable/dump.c
new file mode 100644 (file)
index 0000000..155953d
--- /dev/null
+++ b/reftable/dump.c
@@ -0,0 +1,107 @@
+/*
+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
+*/
+
+#include "git-compat-util.h"
+#include "hash.h"
+
+#include "reftable-blocksource.h"
+#include "reftable-error.h"
+#include "reftable-merged.h"
+#include "reftable-record.h"
+#include "reftable-tests.h"
+#include "reftable-writer.h"
+#include "reftable-iterator.h"
+#include "reftable-reader.h"
+#include "reftable-stack.h"
+#include "reftable-generic.h"
+
+#include <stddef.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <string.h>
+
+static int compact_stack(const char *stackdir)
+{
+       struct reftable_stack *stack = NULL;
+       struct reftable_write_options cfg = { 0 };
+
+       int err = reftable_new_stack(&stack, stackdir, cfg);
+       if (err < 0)
+               goto done;
+
+       err = reftable_stack_compact_all(stack, NULL);
+       if (err < 0)
+               goto done;
+done:
+       if (stack) {
+               reftable_stack_destroy(stack);
+       }
+       return err;
+}
+
+static void print_help(void)
+{
+       printf("usage: dump [-cst] arg\n\n"
+              "options: \n"
+              "  -c compact\n"
+              "  -t dump table\n"
+              "  -s dump stack\n"
+              "  -6 sha256 hash format\n"
+              "  -h this help\n"
+              "\n");
+}
+
+int reftable_dump_main(int argc, char *const *argv)
+{
+       int err = 0;
+       int opt_dump_table = 0;
+       int opt_dump_stack = 0;
+       int opt_compact = 0;
+       uint32_t opt_hash_id = GIT_SHA1_FORMAT_ID;
+       const char *arg = NULL, *argv0 = argv[0];
+
+       for (; argc > 1; argv++, argc--)
+               if (*argv[1] != '-')
+                       break;
+               else if (!strcmp("-t", argv[1]))
+                       opt_dump_table = 1;
+               else if (!strcmp("-6", argv[1]))
+                       opt_hash_id = GIT_SHA256_FORMAT_ID;
+               else if (!strcmp("-s", argv[1]))
+                       opt_dump_stack = 1;
+               else if (!strcmp("-c", argv[1]))
+                       opt_compact = 1;
+               else if (!strcmp("-?", argv[1]) || !strcmp("-h", argv[1])) {
+                       print_help();
+                       return 2;
+               }
+
+       if (argc != 2) {
+               fprintf(stderr, "need argument\n");
+               print_help();
+               return 2;
+       }
+
+       arg = argv[1];
+
+       if (opt_dump_table) {
+               err = reftable_reader_print_file(arg);
+       } else if (opt_dump_stack) {
+               err = reftable_stack_print_directory(arg, opt_hash_id);
+       } else if (opt_compact) {
+               err = compact_stack(arg);
+       }
+
+       if (err < 0) {
+               fprintf(stderr, "%s: %s: %s\n", argv0, arg,
+                       reftable_error_str(err));
+               return 1;
+       }
+       return 0;
+}