From 58841ef12f6cba1bb622353c1fcaa0e3c6fb46c9 Mon Sep 17 00:00:00 2001 From: Ilya Zhuravlev Date: Tue, 23 Oct 2012 01:18:44 +0400 Subject: Add dummy and LevelDB database backends --- src/leveldb/db/c.cc | 595 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 595 insertions(+) create mode 100644 src/leveldb/db/c.cc (limited to 'src/leveldb/db/c.cc') diff --git a/src/leveldb/db/c.cc b/src/leveldb/db/c.cc new file mode 100644 index 000000000..08ff0ad90 --- /dev/null +++ b/src/leveldb/db/c.cc @@ -0,0 +1,595 @@ +// Copyright (c) 2011 The LevelDB Authors. All rights reserved. +// Use of this source code is governed by a BSD-style license that can be +// found in the LICENSE file. See the AUTHORS file for names of contributors. + +#include "leveldb/c.h" + +#include +#include +#include "leveldb/cache.h" +#include "leveldb/comparator.h" +#include "leveldb/db.h" +#include "leveldb/env.h" +#include "leveldb/filter_policy.h" +#include "leveldb/iterator.h" +#include "leveldb/options.h" +#include "leveldb/status.h" +#include "leveldb/write_batch.h" + +using leveldb::Cache; +using leveldb::Comparator; +using leveldb::CompressionType; +using leveldb::DB; +using leveldb::Env; +using leveldb::FileLock; +using leveldb::FilterPolicy; +using leveldb::Iterator; +using leveldb::kMajorVersion; +using leveldb::kMinorVersion; +using leveldb::Logger; +using leveldb::NewBloomFilterPolicy; +using leveldb::NewLRUCache; +using leveldb::Options; +using leveldb::RandomAccessFile; +using leveldb::Range; +using leveldb::ReadOptions; +using leveldb::SequentialFile; +using leveldb::Slice; +using leveldb::Snapshot; +using leveldb::Status; +using leveldb::WritableFile; +using leveldb::WriteBatch; +using leveldb::WriteOptions; + +extern "C" { + +struct leveldb_t { DB* rep; }; +struct leveldb_iterator_t { Iterator* rep; }; +struct leveldb_writebatch_t { WriteBatch rep; }; +struct leveldb_snapshot_t { const Snapshot* rep; }; +struct leveldb_readoptions_t { ReadOptions rep; }; +struct leveldb_writeoptions_t { WriteOptions rep; }; +struct leveldb_options_t { Options rep; }; +struct leveldb_cache_t { Cache* rep; }; +struct leveldb_seqfile_t { SequentialFile* rep; }; +struct leveldb_randomfile_t { RandomAccessFile* rep; }; +struct leveldb_writablefile_t { WritableFile* rep; }; +struct leveldb_logger_t { Logger* rep; }; +struct leveldb_filelock_t { FileLock* rep; }; + +struct leveldb_comparator_t : public Comparator { + void* state_; + void (*destructor_)(void*); + int (*compare_)( + void*, + const char* a, size_t alen, + const char* b, size_t blen); + const char* (*name_)(void*); + + virtual ~leveldb_comparator_t() { + (*destructor_)(state_); + } + + virtual int Compare(const Slice& a, const Slice& b) const { + return (*compare_)(state_, a.data(), a.size(), b.data(), b.size()); + } + + virtual const char* Name() const { + return (*name_)(state_); + } + + // No-ops since the C binding does not support key shortening methods. + virtual void FindShortestSeparator(std::string*, const Slice&) const { } + virtual void FindShortSuccessor(std::string* key) const { } +}; + +struct leveldb_filterpolicy_t : public FilterPolicy { + void* state_; + void (*destructor_)(void*); + const char* (*name_)(void*); + char* (*create_)( + void*, + const char* const* key_array, const size_t* key_length_array, + int num_keys, + size_t* filter_length); + unsigned char (*key_match_)( + void*, + const char* key, size_t length, + const char* filter, size_t filter_length); + + virtual ~leveldb_filterpolicy_t() { + (*destructor_)(state_); + } + + virtual const char* Name() const { + return (*name_)(state_); + } + + virtual void CreateFilter(const Slice* keys, int n, std::string* dst) const { + std::vector key_pointers(n); + std::vector key_sizes(n); + for (int i = 0; i < n; i++) { + key_pointers[i] = keys[i].data(); + key_sizes[i] = keys[i].size(); + } + size_t len; + char* filter = (*create_)(state_, &key_pointers[0], &key_sizes[0], n, &len); + dst->append(filter, len); + free(filter); + } + + virtual bool KeyMayMatch(const Slice& key, const Slice& filter) const { + return (*key_match_)(state_, key.data(), key.size(), + filter.data(), filter.size()); + } +}; + +struct leveldb_env_t { + Env* rep; + bool is_default; +}; + +static bool SaveError(char** errptr, const Status& s) { + assert(errptr != NULL); + if (s.ok()) { + return false; + } else if (*errptr == NULL) { + *errptr = strdup(s.ToString().c_str()); + } else { + // TODO(sanjay): Merge with existing error? + free(*errptr); + *errptr = strdup(s.ToString().c_str()); + } + return true; +} + +static char* CopyString(const std::string& str) { + char* result = reinterpret_cast(malloc(sizeof(char) * str.size())); + memcpy(result, str.data(), sizeof(char) * str.size()); + return result; +} + +leveldb_t* leveldb_open( + const leveldb_options_t* options, + const char* name, + char** errptr) { + DB* db; + if (SaveError(errptr, DB::Open(options->rep, std::string(name), &db))) { + return NULL; + } + leveldb_t* result = new leveldb_t; + result->rep = db; + return result; +} + +void leveldb_close(leveldb_t* db) { + delete db->rep; + delete db; +} + +void leveldb_put( + leveldb_t* db, + const leveldb_writeoptions_t* options, + const char* key, size_t keylen, + const char* val, size_t vallen, + char** errptr) { + SaveError(errptr, + db->rep->Put(options->rep, Slice(key, keylen), Slice(val, vallen))); +} + +void leveldb_delete( + leveldb_t* db, + const leveldb_writeoptions_t* options, + const char* key, size_t keylen, + char** errptr) { + SaveError(errptr, db->rep->Delete(options->rep, Slice(key, keylen))); +} + + +void leveldb_write( + leveldb_t* db, + const leveldb_writeoptions_t* options, + leveldb_writebatch_t* batch, + char** errptr) { + SaveError(errptr, db->rep->Write(options->rep, &batch->rep)); +} + +char* leveldb_get( + leveldb_t* db, + const leveldb_readoptions_t* options, + const char* key, size_t keylen, + size_t* vallen, + char** errptr) { + char* result = NULL; + std::string tmp; + Status s = db->rep->Get(options->rep, Slice(key, keylen), &tmp); + if (s.ok()) { + *vallen = tmp.size(); + result = CopyString(tmp); + } else { + *vallen = 0; + if (!s.IsNotFound()) { + SaveError(errptr, s); + } + } + return result; +} + +leveldb_iterator_t* leveldb_create_iterator( + leveldb_t* db, + const leveldb_readoptions_t* options) { + leveldb_iterator_t* result = new leveldb_iterator_t; + result->rep = db->rep->NewIterator(options->rep); + return result; +} + +const leveldb_snapshot_t* leveldb_create_snapshot( + leveldb_t* db) { + leveldb_snapshot_t* result = new leveldb_snapshot_t; + result->rep = db->rep->GetSnapshot(); + return result; +} + +void leveldb_release_snapshot( + leveldb_t* db, + const leveldb_snapshot_t* snapshot) { + db->rep->ReleaseSnapshot(snapshot->rep); + delete snapshot; +} + +char* leveldb_property_value( + leveldb_t* db, + const char* propname) { + std::string tmp; + if (db->rep->GetProperty(Slice(propname), &tmp)) { + // We use strdup() since we expect human readable output. + return strdup(tmp.c_str()); + } else { + return NULL; + } +} + +void leveldb_approximate_sizes( + leveldb_t* db, + int num_ranges, + const char* const* range_start_key, const size_t* range_start_key_len, + const char* const* range_limit_key, const size_t* range_limit_key_len, + uint64_t* sizes) { + Range* ranges = new Range[num_ranges]; + for (int i = 0; i < num_ranges; i++) { + ranges[i].start = Slice(range_start_key[i], range_start_key_len[i]); + ranges[i].limit = Slice(range_limit_key[i], range_limit_key_len[i]); + } + db->rep->GetApproximateSizes(ranges, num_ranges, sizes); + delete[] ranges; +} + +void leveldb_compact_range( + leveldb_t* db, + const char* start_key, size_t start_key_len, + const char* limit_key, size_t limit_key_len) { + Slice a, b; + db->rep->CompactRange( + // Pass NULL Slice if corresponding "const char*" is NULL + (start_key ? (a = Slice(start_key, start_key_len), &a) : NULL), + (limit_key ? (b = Slice(limit_key, limit_key_len), &b) : NULL)); +} + +void leveldb_destroy_db( + const leveldb_options_t* options, + const char* name, + char** errptr) { + SaveError(errptr, DestroyDB(name, options->rep)); +} + +void leveldb_repair_db( + const leveldb_options_t* options, + const char* name, + char** errptr) { + SaveError(errptr, RepairDB(name, options->rep)); +} + +void leveldb_iter_destroy(leveldb_iterator_t* iter) { + delete iter->rep; + delete iter; +} + +unsigned char leveldb_iter_valid(const leveldb_iterator_t* iter) { + return iter->rep->Valid(); +} + +void leveldb_iter_seek_to_first(leveldb_iterator_t* iter) { + iter->rep->SeekToFirst(); +} + +void leveldb_iter_seek_to_last(leveldb_iterator_t* iter) { + iter->rep->SeekToLast(); +} + +void leveldb_iter_seek(leveldb_iterator_t* iter, const char* k, size_t klen) { + iter->rep->Seek(Slice(k, klen)); +} + +void leveldb_iter_next(leveldb_iterator_t* iter) { + iter->rep->Next(); +} + +void leveldb_iter_prev(leveldb_iterator_t* iter) { + iter->rep->Prev(); +} + +const char* leveldb_iter_key(const leveldb_iterator_t* iter, size_t* klen) { + Slice s = iter->rep->key(); + *klen = s.size(); + return s.data(); +} + +const char* leveldb_iter_value(const leveldb_iterator_t* iter, size_t* vlen) { + Slice s = iter->rep->value(); + *vlen = s.size(); + return s.data(); +} + +void leveldb_iter_get_error(const leveldb_iterator_t* iter, char** errptr) { + SaveError(errptr, iter->rep->status()); +} + +leveldb_writebatch_t* leveldb_writebatch_create() { + return new leveldb_writebatch_t; +} + +void leveldb_writebatch_destroy(leveldb_writebatch_t* b) { + delete b; +} + +void leveldb_writebatch_clear(leveldb_writebatch_t* b) { + b->rep.Clear(); +} + +void leveldb_writebatch_put( + leveldb_writebatch_t* b, + const char* key, size_t klen, + const char* val, size_t vlen) { + b->rep.Put(Slice(key, klen), Slice(val, vlen)); +} + +void leveldb_writebatch_delete( + leveldb_writebatch_t* b, + const char* key, size_t klen) { + b->rep.Delete(Slice(key, klen)); +} + +void leveldb_writebatch_iterate( + leveldb_writebatch_t* b, + void* state, + void (*put)(void*, const char* k, size_t klen, const char* v, size_t vlen), + void (*deleted)(void*, const char* k, size_t klen)) { + class H : public WriteBatch::Handler { + public: + void* state_; + void (*put_)(void*, const char* k, size_t klen, const char* v, size_t vlen); + void (*deleted_)(void*, const char* k, size_t klen); + virtual void Put(const Slice& key, const Slice& value) { + (*put_)(state_, key.data(), key.size(), value.data(), value.size()); + } + virtual void Delete(const Slice& key) { + (*deleted_)(state_, key.data(), key.size()); + } + }; + H handler; + handler.state_ = state; + handler.put_ = put; + handler.deleted_ = deleted; + b->rep.Iterate(&handler); +} + +leveldb_options_t* leveldb_options_create() { + return new leveldb_options_t; +} + +void leveldb_options_destroy(leveldb_options_t* options) { + delete options; +} + +void leveldb_options_set_comparator( + leveldb_options_t* opt, + leveldb_comparator_t* cmp) { + opt->rep.comparator = cmp; +} + +void leveldb_options_set_filter_policy( + leveldb_options_t* opt, + leveldb_filterpolicy_t* policy) { + opt->rep.filter_policy = policy; +} + +void leveldb_options_set_create_if_missing( + leveldb_options_t* opt, unsigned char v) { + opt->rep.create_if_missing = v; +} + +void leveldb_options_set_error_if_exists( + leveldb_options_t* opt, unsigned char v) { + opt->rep.error_if_exists = v; +} + +void leveldb_options_set_paranoid_checks( + leveldb_options_t* opt, unsigned char v) { + opt->rep.paranoid_checks = v; +} + +void leveldb_options_set_env(leveldb_options_t* opt, leveldb_env_t* env) { + opt->rep.env = (env ? env->rep : NULL); +} + +void leveldb_options_set_info_log(leveldb_options_t* opt, leveldb_logger_t* l) { + opt->rep.info_log = (l ? l->rep : NULL); +} + +void leveldb_options_set_write_buffer_size(leveldb_options_t* opt, size_t s) { + opt->rep.write_buffer_size = s; +} + +void leveldb_options_set_max_open_files(leveldb_options_t* opt, int n) { + opt->rep.max_open_files = n; +} + +void leveldb_options_set_cache(leveldb_options_t* opt, leveldb_cache_t* c) { + opt->rep.block_cache = c->rep; +} + +void leveldb_options_set_block_size(leveldb_options_t* opt, size_t s) { + opt->rep.block_size = s; +} + +void leveldb_options_set_block_restart_interval(leveldb_options_t* opt, int n) { + opt->rep.block_restart_interval = n; +} + +void leveldb_options_set_compression(leveldb_options_t* opt, int t) { + opt->rep.compression = static_cast(t); +} + +leveldb_comparator_t* leveldb_comparator_create( + void* state, + void (*destructor)(void*), + int (*compare)( + void*, + const char* a, size_t alen, + const char* b, size_t blen), + const char* (*name)(void*)) { + leveldb_comparator_t* result = new leveldb_comparator_t; + result->state_ = state; + result->destructor_ = destructor; + result->compare_ = compare; + result->name_ = name; + return result; +} + +void leveldb_comparator_destroy(leveldb_comparator_t* cmp) { + delete cmp; +} + +leveldb_filterpolicy_t* leveldb_filterpolicy_create( + void* state, + void (*destructor)(void*), + char* (*create_filter)( + void*, + const char* const* key_array, const size_t* key_length_array, + int num_keys, + size_t* filter_length), + unsigned char (*key_may_match)( + void*, + const char* key, size_t length, + const char* filter, size_t filter_length), + const char* (*name)(void*)) { + leveldb_filterpolicy_t* result = new leveldb_filterpolicy_t; + result->state_ = state; + result->destructor_ = destructor; + result->create_ = create_filter; + result->key_match_ = key_may_match; + result->name_ = name; + return result; +} + +void leveldb_filterpolicy_destroy(leveldb_filterpolicy_t* filter) { + delete filter; +} + +leveldb_filterpolicy_t* leveldb_filterpolicy_create_bloom(int bits_per_key) { + // Make a leveldb_filterpolicy_t, but override all of its methods so + // they delegate to a NewBloomFilterPolicy() instead of user + // supplied C functions. + struct Wrapper : public leveldb_filterpolicy_t { + const FilterPolicy* rep_; + ~Wrapper() { delete rep_; } + const char* Name() const { return rep_->Name(); } + void CreateFilter(const Slice* keys, int n, std::string* dst) const { + return rep_->CreateFilter(keys, n, dst); + } + bool KeyMayMatch(const Slice& key, const Slice& filter) const { + return rep_->KeyMayMatch(key, filter); + } + static void DoNothing(void*) { } + }; + Wrapper* wrapper = new Wrapper; + wrapper->rep_ = NewBloomFilterPolicy(bits_per_key); + wrapper->state_ = NULL; + wrapper->destructor_ = &Wrapper::DoNothing; + return wrapper; +} + +leveldb_readoptions_t* leveldb_readoptions_create() { + return new leveldb_readoptions_t; +} + +void leveldb_readoptions_destroy(leveldb_readoptions_t* opt) { + delete opt; +} + +void leveldb_readoptions_set_verify_checksums( + leveldb_readoptions_t* opt, + unsigned char v) { + opt->rep.verify_checksums = v; +} + +void leveldb_readoptions_set_fill_cache( + leveldb_readoptions_t* opt, unsigned char v) { + opt->rep.fill_cache = v; +} + +void leveldb_readoptions_set_snapshot( + leveldb_readoptions_t* opt, + const leveldb_snapshot_t* snap) { + opt->rep.snapshot = (snap ? snap->rep : NULL); +} + +leveldb_writeoptions_t* leveldb_writeoptions_create() { + return new leveldb_writeoptions_t; +} + +void leveldb_writeoptions_destroy(leveldb_writeoptions_t* opt) { + delete opt; +} + +void leveldb_writeoptions_set_sync( + leveldb_writeoptions_t* opt, unsigned char v) { + opt->rep.sync = v; +} + +leveldb_cache_t* leveldb_cache_create_lru(size_t capacity) { + leveldb_cache_t* c = new leveldb_cache_t; + c->rep = NewLRUCache(capacity); + return c; +} + +void leveldb_cache_destroy(leveldb_cache_t* cache) { + delete cache->rep; + delete cache; +} + +leveldb_env_t* leveldb_create_default_env() { + leveldb_env_t* result = new leveldb_env_t; + result->rep = Env::Default(); + result->is_default = true; + return result; +} + +void leveldb_env_destroy(leveldb_env_t* env) { + if (!env->is_default) delete env->rep; + delete env; +} + +void leveldb_free(void* ptr) { + free(ptr); +} + +int leveldb_major_version() { + return kMajorVersion; +} + +int leveldb_minor_version() { + return kMinorVersion; +} + +} // end extern "C" -- cgit v1.2.3