| 1 | /* |
| 2 | * Copyright 2020 Google LLC |
| 3 | * |
| 4 | * Use of this source code is governed by a BSD-style |
| 5 | * license that can be found in the LICENSE file or at |
| 6 | * https://developers.google.com/open-source/licenses/bsd |
| 7 | */ |
| 8 | |
| 9 | #ifndef REFTABLE_WRITER_H |
| 10 | #define REFTABLE_WRITER_H |
| 11 | |
| 12 | #include "reftable-system.h" |
| 13 | #include "reftable-record.h" |
| 14 | |
| 15 | /* Writing single reftables */ |
| 16 | |
| 17 | /* reftable_write_options sets options for writing a single reftable. */ |
| 18 | struct reftable_write_options { |
| 19 | /* boolean: do not pad out blocks to block size. */ |
| 20 | unsigned unpadded : 1; |
| 21 | |
| 22 | /* the blocksize. Should be less than 2^24. */ |
| 23 | uint32_t block_size; |
| 24 | |
| 25 | /* boolean: do not generate a SHA1 => ref index. */ |
| 26 | unsigned skip_index_objects : 1; |
| 27 | |
| 28 | /* how often to write complete keys in each block. */ |
| 29 | uint16_t restart_interval; |
| 30 | |
| 31 | /* Default mode for creating files. If unset, use 0666 (+umask) */ |
| 32 | unsigned int default_permissions; |
| 33 | |
| 34 | /* boolean: copy log messages exactly. If unset, check that the message |
| 35 | * is a single line, and add '\n' if missing. |
| 36 | */ |
| 37 | unsigned exact_log_message : 1; |
| 38 | |
| 39 | /* boolean: Prevent auto-compaction of tables. */ |
| 40 | unsigned disable_auto_compact : 1; |
| 41 | |
| 42 | /* |
| 43 | * Geometric sequence factor used by auto-compaction to decide which |
| 44 | * tables to compact. Defaults to 2 if unset. |
| 45 | */ |
| 46 | uint8_t auto_compaction_factor; |
| 47 | |
| 48 | /* |
| 49 | * The number of milliseconds to wait when trying to lock "tables.list". |
| 50 | * Note that this does not apply to locking individual tables, as these |
| 51 | * should only ever be locked when already holding the "tables.list" |
| 52 | * lock. |
| 53 | * |
| 54 | * Passing 0 will fail immediately when the file is locked, passing a |
| 55 | * negative value will cause us to block indefinitely. |
| 56 | */ |
| 57 | long lock_timeout_ms; |
| 58 | }; |
| 59 | |
| 60 | /* reftable_block_stats holds statistics for a single block type */ |
| 61 | struct reftable_block_stats { |
| 62 | /* total number of entries written */ |
| 63 | int entries; |
| 64 | /* total number of key restarts */ |
| 65 | uint32_t restarts; |
| 66 | /* total number of blocks */ |
| 67 | int blocks; |
| 68 | /* total number of index blocks */ |
| 69 | int index_blocks; |
| 70 | /* depth of the index */ |
| 71 | int max_index_level; |
| 72 | |
| 73 | /* offset of the first block for this type */ |
| 74 | uint64_t offset; |
| 75 | /* offset of the top level index block for this type, or 0 if not |
| 76 | * present */ |
| 77 | uint64_t index_offset; |
| 78 | }; |
| 79 | |
| 80 | /* stats holds overall statistics for a single reftable */ |
| 81 | struct reftable_stats { |
| 82 | /* total number of blocks written. */ |
| 83 | int blocks; |
| 84 | /* stats for ref data */ |
| 85 | struct reftable_block_stats ref_stats; |
| 86 | /* stats for the SHA1 to ref map. */ |
| 87 | struct reftable_block_stats obj_stats; |
| 88 | /* stats for index blocks */ |
| 89 | struct reftable_block_stats idx_stats; |
| 90 | /* stats for log blocks */ |
| 91 | struct reftable_block_stats log_stats; |
| 92 | |
| 93 | /* disambiguation length of shortened object IDs. */ |
| 94 | int object_id_len; |
| 95 | }; |
| 96 | |
| 97 | struct reftable_writer; |
| 98 | |
| 99 | /* Create a new writer. */ |
| 100 | int reftable_writer_new(struct reftable_writer **out, |
| 101 | ssize_t (*writer_func)(void *, const void *, size_t), |
| 102 | int (*flush_func)(void *), |
| 103 | void *writer_arg, enum reftable_hash hash_id, |
| 104 | const struct reftable_write_options *opts); |
| 105 | |
| 106 | /* |
| 107 | * Set the range of update indices for the records we will add. When writing a |
| 108 | * table into a stack, the min should be at least |
| 109 | * reftable_stack_next_update_index(), or REFTABLE_API_ERROR is returned. |
| 110 | * |
| 111 | * For transactional updates to a stack, typically min==max, and the |
| 112 | * update_index can be obtained by inspeciting the stack. When converting an |
| 113 | * existing ref database into a single reftable, this would be a range of |
| 114 | * update-index timestamps. |
| 115 | * |
| 116 | * The function should be called before adding any records to the writer. If not |
| 117 | * it will fail with REFTABLE_API_ERROR. |
| 118 | */ |
| 119 | int reftable_writer_set_limits(struct reftable_writer *w, uint64_t min, |
| 120 | uint64_t max); |
| 121 | |
| 122 | /* |
| 123 | Add a reftable_ref_record. The record should have names that come after |
| 124 | already added records. |
| 125 | |
| 126 | The update_index must be within the limits set by |
| 127 | reftable_writer_set_limits(), or REFTABLE_API_ERROR is returned. It is an |
| 128 | REFTABLE_API_ERROR error to write a ref record after a log record. |
| 129 | */ |
| 130 | int reftable_writer_add_ref(struct reftable_writer *w, |
| 131 | struct reftable_ref_record *ref); |
| 132 | |
| 133 | /* |
| 134 | Convenience function to add multiple reftable_ref_records; the function sorts |
| 135 | the records before adding them, reordering the records array passed in. |
| 136 | */ |
| 137 | int reftable_writer_add_refs(struct reftable_writer *w, |
| 138 | struct reftable_ref_record *refs, size_t n); |
| 139 | |
| 140 | /* |
| 141 | adds reftable_log_records. Log records are keyed by (refname, decreasing |
| 142 | update_index). The key for the record added must come after the already added |
| 143 | log records. |
| 144 | */ |
| 145 | int reftable_writer_add_log(struct reftable_writer *w, |
| 146 | struct reftable_log_record *log); |
| 147 | |
| 148 | /* |
| 149 | Convenience function to add multiple reftable_log_records; the function sorts |
| 150 | the records before adding them, reordering records array passed in. |
| 151 | */ |
| 152 | int reftable_writer_add_logs(struct reftable_writer *w, |
| 153 | struct reftable_log_record *logs, size_t n); |
| 154 | |
| 155 | /* reftable_writer_close finalizes the reftable. The writer is retained so |
| 156 | * statistics can be inspected. */ |
| 157 | int reftable_writer_close(struct reftable_writer *w); |
| 158 | |
| 159 | /* writer_stats returns the statistics on the reftable being written. |
| 160 | |
| 161 | This struct becomes invalid when the writer is freed. |
| 162 | */ |
| 163 | const struct reftable_stats *reftable_writer_stats(struct reftable_writer *w); |
| 164 | |
| 165 | /* reftable_writer_free deallocates memory for the writer */ |
| 166 | void reftable_writer_free(struct reftable_writer *w); |
| 167 | |
| 168 | #endif |