From 46bc0e731a70716485bc3c8bdaf7e6e6f88073a9 Mon Sep 17 00:00:00 2001 From: Han-Wen Nienhuys Date: Thu, 7 Oct 2021 20:25:08 +0000 Subject: reftable: read reftable files This supports reading a single reftable file. The commit introduces an abstract iterator type, which captures the usecases both of reading individual refs, and iterating over a segment of the ref namespace. Signed-off-by: Han-Wen Nienhuys Signed-off-by: Junio C Hamano --- reftable/reftable-reader.h | 101 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 101 insertions(+) create mode 100644 reftable/reftable-reader.h (limited to 'reftable/reftable-reader.h') diff --git a/reftable/reftable-reader.h b/reftable/reftable-reader.h new file mode 100644 index 0000000000..4a4bc2fdf8 --- /dev/null +++ b/reftable/reftable-reader.h @@ -0,0 +1,101 @@ +/* + 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 REFTABLE_READER_H +#define REFTABLE_READER_H + +#include "reftable-iterator.h" +#include "reftable-blocksource.h" + +/* + * Reading single tables + * + * The follow routines are for reading single files. For an + * application-level interface, skip ahead to struct + * reftable_merged_table and struct reftable_stack. + */ + +/* The reader struct is a handle to an open reftable file. */ +struct reftable_reader; + +/* Generic table. */ +struct reftable_table; + +/* reftable_new_reader opens a reftable for reading. If successful, + * returns 0 code and sets pp. The name is used for creating a + * stack. Typically, it is the basename of the file. The block source + * `src` is owned by the reader, and is closed on calling + * reftable_reader_destroy(). On error, the block source `src` is + * closed as well. + */ +int reftable_new_reader(struct reftable_reader **pp, + struct reftable_block_source *src, const char *name); + +/* reftable_reader_seek_ref returns an iterator where 'name' would be inserted + in the table. To seek to the start of the table, use name = "". + + example: + + struct reftable_reader *r = NULL; + int err = reftable_new_reader(&r, &src, "filename"); + if (err < 0) { ... } + struct reftable_iterator it = {0}; + err = reftable_reader_seek_ref(r, &it, "refs/heads/master"); + if (err < 0) { ... } + struct reftable_ref_record ref = {0}; + while (1) { + err = reftable_iterator_next_ref(&it, &ref); + if (err > 0) { + break; + } + if (err < 0) { + ..error handling.. + } + ..found.. + } + reftable_iterator_destroy(&it); + reftable_ref_record_release(&ref); +*/ +int reftable_reader_seek_ref(struct reftable_reader *r, + struct reftable_iterator *it, const char *name); + +/* returns the hash ID used in this table. */ +uint32_t reftable_reader_hash_id(struct reftable_reader *r); + +/* seek to logs for the given name, older than update_index. To seek to the + start of the table, use name = "". +*/ +int reftable_reader_seek_log_at(struct reftable_reader *r, + struct reftable_iterator *it, const char *name, + uint64_t update_index); + +/* seek to newest log entry for given name. */ +int reftable_reader_seek_log(struct reftable_reader *r, + struct reftable_iterator *it, const char *name); + +/* closes and deallocates a reader. */ +void reftable_reader_free(struct reftable_reader *); + +/* return an iterator for the refs pointing to `oid`. */ +int reftable_reader_refs_for(struct reftable_reader *r, + struct reftable_iterator *it, uint8_t *oid); + +/* return the max_update_index for a table */ +uint64_t reftable_reader_max_update_index(struct reftable_reader *r); + +/* return the min_update_index for a table */ +uint64_t reftable_reader_min_update_index(struct reftable_reader *r); + +/* creates a generic table from a file reader. */ +void reftable_table_from_reader(struct reftable_table *tab, + struct reftable_reader *reader); + +/* print table onto stdout for debugging. */ +int reftable_reader_print_file(const char *tablename); + +#endif -- cgit v1.2.3