reftable/iter.h

   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 #include "reftable-generic.h"
  18
  19 /* Returns true for a zeroed out iterator, such as the one returned from
  20  * iterator_destroy. */
  21 int iterator_is_null(struct reftable_iterator *it);
  22
  23 /* iterator that produces only ref records that point to `oid` */
  24 struct filtering_ref_iterator {
  25         int double_check;
  26         struct reftable_table tab;
  27         struct strbuf oid;
  28         struct reftable_iterator it;
  29 };
  30 #define FILTERING_REF_ITERATOR_INIT \
  31         {                           \
  32                 .oid = STRBUF_INIT  \
  33         }
  34
  35 void iterator_from_filtering_ref_iterator(struct reftable_iterator *,
  36                                           struct filtering_ref_iterator *);
  37
  38 /* iterator that produces only ref records that point to `oid`,
  39  * but using the object index.
  40  */
  41 struct indexed_table_ref_iter {
  42         struct reftable_reader *r;
  43         struct strbuf oid;
  44
  45         /* mutable */
  46         uint64_t *offsets;
  47
  48         /* Points to the next offset to read. */
  49         int offset_idx;
  50         int offset_len;
  51         struct block_reader block_reader;
  52         struct block_iter cur;
  53         int is_finished;
  54 };
  55
  56 #define INDEXED_TABLE_REF_ITER_INIT { \
  57         .cur = BLOCK_ITER_INIT, \
  58         .oid = STRBUF_INIT, \
  59 }
  60
  61 void iterator_from_indexed_table_ref_iter(struct reftable_iterator *it,
  62                                           struct indexed_table_ref_iter *itr);
  63
  64 /* Takes ownership of `offsets` */
  65 int new_indexed_table_ref_iter(struct indexed_table_ref_iter **dest,
  66                                struct reftable_reader *r, uint8_t *oid,
  67                                int oid_len, uint64_t *offsets, int offset_len);
  68
  69 #endif