90 lines
2.3 KiB
C
90 lines
2.3 KiB
C
/*
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Copyright 2020 Google LLC
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Use of this source code is governed by a BSD-style
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license that can be found in the LICENSE file or at
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https://developers.google.com/open-source/licenses/bsd
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*/
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#ifndef ITER_H
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#define ITER_H
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#include "system.h"
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#include "block.h"
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#include "record.h"
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#include "reftable-iterator.h"
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/*
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* The virtual function table for implementing generic reftable iterators.
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*/
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struct reftable_iterator_vtable {
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int (*seek)(void *iter_arg, struct reftable_record *want);
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int (*next)(void *iter_arg, struct reftable_record *rec);
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void (*close)(void *iter_arg);
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};
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/*
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* Position the iterator at the wanted record such that a call to
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* `iterator_next()` would return that record, if it exists.
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*/
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int iterator_seek(struct reftable_iterator *it, struct reftable_record *want);
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/*
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* Yield the next record and advance the iterator. Returns <0 on error, 0 when
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* a record was yielded, and >0 when the iterator hit an error.
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*/
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int iterator_next(struct reftable_iterator *it, struct reftable_record *rec);
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/*
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* Set up the iterator such that it behaves the same as an iterator with no
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* entries.
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*/
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void iterator_set_empty(struct reftable_iterator *it);
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/* iterator that produces only ref records that point to `oid` */
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struct filtering_ref_iterator {
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struct reftable_buf oid;
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struct reftable_iterator it;
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};
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#define FILTERING_REF_ITERATOR_INIT \
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{ \
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.oid = REFTABLE_BUF_INIT \
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}
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void iterator_from_filtering_ref_iterator(struct reftable_iterator *,
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struct filtering_ref_iterator *);
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/* iterator that produces only ref records that point to `oid`,
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* but using the object index.
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*/
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struct indexed_table_ref_iter {
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struct reftable_reader *r;
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struct reftable_buf oid;
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/* mutable */
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uint64_t *offsets;
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/* Points to the next offset to read. */
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int offset_idx;
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int offset_len;
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struct block_reader block_reader;
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struct block_iter cur;
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int is_finished;
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};
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#define INDEXED_TABLE_REF_ITER_INIT { \
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.cur = BLOCK_ITER_INIT, \
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.oid = REFTABLE_BUF_INIT, \
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}
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void iterator_from_indexed_table_ref_iter(struct reftable_iterator *it,
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struct indexed_table_ref_iter *itr);
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/* Takes ownership of `offsets` */
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int indexed_table_ref_iter_new(struct indexed_table_ref_iter **dest,
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struct reftable_reader *r, uint8_t *oid,
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int oid_len, uint64_t *offsets, int offset_len);
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#endif
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