reftable/reftable-iterator.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 REFTABLE_ITERATOR_H
  10 #define REFTABLE_ITERATOR_H
  11
  12 #include "reftable-record.h"
  13
  14 struct reftable_iterator_vtable;
  15
  16 /* iterator is the generic interface for walking over data stored in a
  17  * reftable.
  18  */
  19 struct reftable_iterator {
  20         struct reftable_iterator_vtable *ops;
  21         void *iter_arg;
  22 };
  23
  24 /*
  25  * Position the iterator at the ref record with given name such that the next
  26  * call to `next_ref()` would yield the record.
  27  */
  28 int reftable_iterator_seek_ref(struct reftable_iterator *it,
  29                                const char *name);
  30
  31 /* reads the next reftable_ref_record. Returns < 0 for error, 0 for OK and > 0:
  32  * end of iteration.
  33  */
  34 int reftable_iterator_next_ref(struct reftable_iterator *it,
  35                                struct reftable_ref_record *ref);
  36
  37 /*
  38  * Position the iterator at the log record with given name and update index
  39  * such that the next call to `next_log()` would yield the record.
  40  */
  41 int reftable_iterator_seek_log_at(struct reftable_iterator *it,
  42                                   const char *name, uint64_t update_index);
  43
  44 /*
  45  * Position the iterator at the newest log record with given name such that the
  46  * next call to `next_log()` would yield the record.
  47  */
  48 int reftable_iterator_seek_log(struct reftable_iterator *it,
  49                                const char *name);
  50
  51 /* reads the next reftable_log_record. Returns < 0 for error, 0 for OK and > 0:
  52  * end of iteration.
  53  */
  54 int reftable_iterator_next_log(struct reftable_iterator *it,
  55                                struct reftable_log_record *log);
  56
  57 /* releases resources associated with an iterator. */
  58 void reftable_iterator_destroy(struct reftable_iterator *it);
  59
  60 #endif