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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-21 11:54:28 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-21 11:54:28 +0000 |
commit | e6918187568dbd01842d8d1d2c808ce16a894239 (patch) | |
tree | 64f88b554b444a49f656b6c656111a145cbbaa28 /src/rocksdb/examples/simple_example.cc | |
parent | Initial commit. (diff) | |
download | ceph-e6918187568dbd01842d8d1d2c808ce16a894239.tar.xz ceph-e6918187568dbd01842d8d1d2c808ce16a894239.zip |
Adding upstream version 18.2.2.upstream/18.2.2
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r-- | src/rocksdb/examples/simple_example.cc | 93 |
1 files changed, 93 insertions, 0 deletions
diff --git a/src/rocksdb/examples/simple_example.cc b/src/rocksdb/examples/simple_example.cc new file mode 100644 index 000000000..2d49c4d14 --- /dev/null +++ b/src/rocksdb/examples/simple_example.cc @@ -0,0 +1,93 @@ +// Copyright (c) 2011-present, Facebook, Inc. All rights reserved. +// This source code is licensed under both the GPLv2 (found in the +// COPYING file in the root directory) and Apache 2.0 License +// (found in the LICENSE.Apache file in the root directory). + +#include <cstdio> +#include <string> + +#include "rocksdb/db.h" +#include "rocksdb/options.h" +#include "rocksdb/slice.h" + +using ROCKSDB_NAMESPACE::DB; +using ROCKSDB_NAMESPACE::Options; +using ROCKSDB_NAMESPACE::PinnableSlice; +using ROCKSDB_NAMESPACE::ReadOptions; +using ROCKSDB_NAMESPACE::Status; +using ROCKSDB_NAMESPACE::WriteBatch; +using ROCKSDB_NAMESPACE::WriteOptions; + +#if defined(OS_WIN) +std::string kDBPath = "C:\\Windows\\TEMP\\rocksdb_simple_example"; +#else +std::string kDBPath = "/tmp/rocksdb_simple_example"; +#endif + +int main() { + DB* db; + Options options; + // Optimize RocksDB. This is the easiest way to get RocksDB to perform well + options.IncreaseParallelism(); + options.OptimizeLevelStyleCompaction(); + // create the DB if it's not already present + options.create_if_missing = true; + + // open DB + Status s = DB::Open(options, kDBPath, &db); + assert(s.ok()); + + // Put key-value + s = db->Put(WriteOptions(), "key1", "value"); + assert(s.ok()); + std::string value; + // get value + s = db->Get(ReadOptions(), "key1", &value); + assert(s.ok()); + assert(value == "value"); + + // atomically apply a set of updates + { + WriteBatch batch; + batch.Delete("key1"); + batch.Put("key2", value); + s = db->Write(WriteOptions(), &batch); + } + + s = db->Get(ReadOptions(), "key1", &value); + assert(s.IsNotFound()); + + db->Get(ReadOptions(), "key2", &value); + assert(value == "value"); + + { + PinnableSlice pinnable_val; + db->Get(ReadOptions(), db->DefaultColumnFamily(), "key2", &pinnable_val); + assert(pinnable_val == "value"); + } + + { + std::string string_val; + // If it cannot pin the value, it copies the value to its internal buffer. + // The intenral buffer could be set during construction. + PinnableSlice pinnable_val(&string_val); + db->Get(ReadOptions(), db->DefaultColumnFamily(), "key2", &pinnable_val); + assert(pinnable_val == "value"); + // If the value is not pinned, the internal buffer must have the value. + assert(pinnable_val.IsPinned() || string_val == "value"); + } + + PinnableSlice pinnable_val; + s = db->Get(ReadOptions(), db->DefaultColumnFamily(), "key1", &pinnable_val); + assert(s.IsNotFound()); + // Reset PinnableSlice after each use and before each reuse + pinnable_val.Reset(); + db->Get(ReadOptions(), db->DefaultColumnFamily(), "key2", &pinnable_val); + assert(pinnable_val == "value"); + pinnable_val.Reset(); + // The Slice pointed by pinnable_val is not valid after this point + + delete db; + + return 0; +} |