From e6918187568dbd01842d8d1d2c808ce16a894239 Mon Sep 17 00:00:00 2001
From: Daniel Baumann <daniel.baumann@progress-linux.org>
Date: Sun, 21 Apr 2024 13:54:28 +0200
Subject: Adding upstream version 18.2.2.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
---
 src/rocksdb/examples/simple_example.cc | 93 ++++++++++++++++++++++++++++++++++
 1 file changed, 93 insertions(+)
 create mode 100644 src/rocksdb/examples/simple_example.cc

(limited to 'src/rocksdb/examples/simple_example.cc')

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;
+}
-- 
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