| 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 ITER_H |
| 10 | #define ITER_H |
| 11 | |
| 12 | #include "system.h" |
| 13 | #include "block.h" |
| 14 | #include "record.h" |
| 15 | |
| 16 | #include "reftable-iterator.h" |
| 17 | |
| 18 | /* |
| 19 | * The virtual function table for implementing generic reftable iterators. |
| 20 | */ |
| 21 | struct reftable_iterator_vtable { |
| 22 | int (*seek)(void *iter_arg, struct reftable_record *want); |
| 23 | int (*next)(void *iter_arg, struct reftable_record *rec); |
| 24 | void (*close)(void *iter_arg); |
| 25 | }; |
| 26 | |
| 27 | /* |
| 28 | * Position the iterator at the wanted record such that a call to |
| 29 | * `iterator_next()` would return that record, if it exists. |
| 30 | */ |
| 31 | int iterator_seek(struct reftable_iterator *it, struct reftable_record *want); |
| 32 | |
| 33 | /* |
| 34 | * Yield the next record and advance the iterator. Returns <0 on error, 0 when |
| 35 | * a record was yielded, and >0 when the iterator hit an error. |
| 36 | */ |
| 37 | int iterator_next(struct reftable_iterator *it, struct reftable_record *rec); |
| 38 | |
| 39 | /* |
| 40 | * Set up the iterator such that it behaves the same as an iterator with no |
| 41 | * entries. |
| 42 | */ |
| 43 | void iterator_set_empty(struct reftable_iterator *it); |
| 44 | |
| 45 | /* iterator that produces only ref records that point to `oid` */ |
| 46 | struct filtering_ref_iterator { |
| 47 | struct reftable_buf oid; |
| 48 | struct reftable_iterator it; |
| 49 | }; |
| 50 | #define FILTERING_REF_ITERATOR_INIT \ |
| 51 | { \ |
| 52 | .oid = REFTABLE_BUF_INIT \ |
| 53 | } |
| 54 | |
| 55 | void iterator_from_filtering_ref_iterator(struct reftable_iterator *, |
| 56 | struct filtering_ref_iterator *); |
| 57 | |
| 58 | /* iterator that produces only ref records that point to `oid`, |
| 59 | * but using the object index. |
| 60 | */ |
| 61 | struct indexed_table_ref_iter { |
| 62 | struct reftable_table *table; |
| 63 | struct reftable_buf oid; |
| 64 | |
| 65 | /* mutable */ |
| 66 | uint64_t *offsets; |
| 67 | |
| 68 | /* Points to the next offset to read. */ |
| 69 | int offset_idx; |
| 70 | int offset_len; |
| 71 | struct reftable_block block; |
| 72 | struct block_iter cur; |
| 73 | int is_finished; |
| 74 | }; |
| 75 | |
| 76 | #define INDEXED_TABLE_REF_ITER_INIT { \ |
| 77 | .cur = BLOCK_ITER_INIT, \ |
| 78 | .oid = REFTABLE_BUF_INIT, \ |
| 79 | } |
| 80 | |
| 81 | void iterator_from_indexed_table_ref_iter(struct reftable_iterator *it, |
| 82 | struct indexed_table_ref_iter *itr); |
| 83 | |
| 84 | /* Takes ownership of `offsets` */ |
| 85 | int indexed_table_ref_iter_new(struct indexed_table_ref_iter **dest, |
| 86 | struct reftable_table *t, uint8_t *oid, |
| 87 | int oid_len, uint64_t *offsets, int offset_len); |
| 88 | |
| 89 | #endif |