static void RecoverAndTestStore(string path)
{
using var settings = new FasterKVSettings <MyKey, MyValue>(path, deleteDirOnDispose: true)
{
KeySerializer = () => new MyKeySerializer(),
ValueSerializer = () => new MyValueSerializer(),
TryRecoverLatest = true,
};
using var store = new FasterKV <MyKey, MyValue>(settings);
using var session = store.NewSession(new Functions());
// Test Read
var key = new MyKey {
key = 23
};
MyOutput g1 = default;
var status = session.Read(ref key, ref g1);
if (status.Found && g1.value.value == key.key)
{
Console.WriteLine("Success!");
}
else
{
Console.WriteLine("Error!");
}
}
static void PopulateStore(string path)
{
// We use class types MyKey and MyValue in this example, replace with blittable structs for
// better performance. Serializers are required for class (non-blittable) types in order to
// write to storage. You can also mark types as DataContract (lower performance).
using var settings = new FasterKVSettings <MyKey, MyValue>(path)
{
KeySerializer = () => new MyKeySerializer(),
ValueSerializer = () => new MyValueSerializer()
};
using var store = new FasterKV <MyKey, MyValue>(settings);
using var s = store.NewSession(new Functions());
for (int i = 0; i < 20000; i++)
{
var _key = new MyKey {
key = i
};
var value = new MyValue {
value = i
};
s.Upsert(ref _key, ref value);
}
var key = new MyKey {
key = 23
};
MyOutput g1 = default;
var status = s.Read(ref key, ref g1);
if (status.Found && g1.value.value == key.key)
{
Console.WriteLine("Success!");
}
else
{
Console.WriteLine("Error!");
}
// Take index + fold-over checkpoint of FASTER, wait to complete
store.TakeFullCheckpointAsync(CheckpointType.FoldOver).AsTask().GetAwaiter().GetResult();
}
static void InMemorySample()
{
Console.WriteLine("In-Memory Sample:\n");
long key = 1, value = 1, output = 0;
// Create a default config (null path indicates in-memory only)
// Uses default config parameters. Update config fields to tune parameters.
using var config = new FasterKVSettings <long, long>(null);
Console.WriteLine($"FasterKV config:\n{config}\n");
using var store = new FasterKV <long, long>(config);
// Create functions for callbacks; we use a standard in-built function in this sample.
// You can write your own by extending this or FunctionsBase.
// In this in-built function, read-modify-writes will perform value merges via summation.
var funcs = new SimpleFunctions <long, long>((a, b) => a + b);
// Each logical sequence of calls to FASTER is associated with a FASTER session.
// No concurrency allowed within a single session
using var session = store.NewSession(funcs);
// (1) Upsert and read back upserted value
session.Upsert(ref key, ref value);
// Reads are served back from memory and return synchronously
var status = session.Read(ref key, ref output);
if (status.Found && output == value)
{
Console.WriteLine("(1) Success!");
}
else
{
Console.WriteLine("(1) Error!");
}
/// (2) Delete key, read to verify deletion
session.Delete(ref key);
status = session.Read(ref key, ref output);
if (status.Found)
{
Console.WriteLine("(2) Error!");
}
else
{
Console.WriteLine("(2) Success!");
}
// (4) Perform two read-modify-writes (summation), verify result
key = 2;
long input1 = 25, input2 = 27;
session.RMW(ref key, ref input1);
session.RMW(ref key, ref input2);
status = session.Read(ref key, ref output);
if (status.Found && output == input1 + input2)
{
Console.WriteLine("(3) Success!");
}
else
{
Console.WriteLine("(3) Error!");
}
// (5) Perform TryAdd using RMW and custom IFunctions
using var tryAddSession = store.NewSession(new TryAddFunctions <long, long>());
key = 3; input1 = 30; input2 = 31;
// First TryAdd - success; status should be NotFound (does not already exist)
status = tryAddSession.RMW(ref key, ref input1);
// Second TryAdd - failure; status should be Found (already exists)
var status2 = tryAddSession.RMW(ref key, ref input2);
// Read, result should be input1 (first TryAdd)
var status3 = session.Read(ref key, ref output);
if (status.NotFound && status2.Found && status3.Found && output == input1)
{
Console.WriteLine("(4) Success!");
}
else
{
Console.WriteLine("(4) Error!");
}
}
static void DiskSample()
{
Console.WriteLine("\nDisk Sample:\n");
long key = 1, value = 1, output = 0;
// Create FasterKV config based on specified base directory path.
using var config = new FasterKVSettings <long, long>("./database")
{
TryRecoverLatest = true
};
Console.WriteLine($"FasterKV config:\n{config}\n");
// Create store using specified config
using var store = new FasterKV <long, long>(config);
// Create functions for callbacks; we use a standard in-built function in this sample.
// You can write your own by extending this or FunctionsBase.
// In this in-built function, read-modify-writes will perform value merges via summation.
var funcs = new SimpleFunctions <long, long>((a, b) => a + b);
// Each logical sequence of calls to FASTER is associated with a FASTER session.
// No concurrency allowed within a single session
using var session = store.NewSession(funcs);
if (store.RecoveredVersion == 1) // did not recover
{
Console.WriteLine("Clean start; upserting key-value pair");
// (1) Upsert and read back upserted value
session.Upsert(ref key, ref value);
// Take checkpoint so data is persisted for recovery
Console.WriteLine("Taking full checkpoint");
store.TryInitiateFullCheckpoint(out _, CheckpointType.Snapshot);
store.CompleteCheckpointAsync().AsTask().GetAwaiter().GetResult();
}
else
{
Console.WriteLine($"Recovered store to version {store.RecoveredVersion}");
}
// Reads are served back from memory and return synchronously
var status = session.Read(ref key, ref output);
if (status.Found && output == value)
{
Console.WriteLine("(1) Success!");
}
else
{
Console.WriteLine("(1) Error!");
}
// (2) Force flush record to disk and evict from memory, so that next read is served from disk
store.Log.FlushAndEvict(true);
// Reads from disk will return PENDING status, result available via either asynchronous IFunctions callback
// or on this thread via CompletePendingWithOutputs, shown below
status = session.Read(ref key, ref output);
if (status.IsPending)
{
session.CompletePendingWithOutputs(out var iter, true);
while (iter.Next())
{
if (iter.Current.Status.Found && iter.Current.Output == value)
{
Console.WriteLine("(2) Success!");
}
else
{
Console.WriteLine("(2) Error!");
}
}
iter.Dispose();
}
else
{
Console.WriteLine("(2) Error!");
}
/// (3) Delete key, read to verify deletion
session.Delete(ref key);
status = session.Read(ref key, ref output);
if (status.Found)
{
Console.WriteLine("(3) Error!");
}
else
{
Console.WriteLine("(3) Success!");
}
// (4) Perform two read-modify-writes (summation), verify result
key = 2;
long input1 = 25, input2 = 27;
session.RMW(ref key, ref input1);
session.RMW(ref key, ref input2);
status = session.Read(ref key, ref output);
if (status.Found && output == input1 + input2)
{
Console.WriteLine("(4) Success!");
}
else
{
Console.WriteLine("(4) Error!");
}
// (5) Perform TryAdd using RMW and custom IFunctions
using var tryAddSession = store.NewSession(new TryAddFunctions <long, long>());
key = 3; input1 = 30; input2 = 31;
// First TryAdd - success; status should be NOTFOUND (does not already exist)
status = tryAddSession.RMW(ref key, ref input1);
// Second TryAdd - failure; status should be OK (already exists)
var status2 = tryAddSession.RMW(ref key, ref input2);
// Read, result should be input1 (first TryAdd)
var status3 = session.Read(ref key, ref output);
if (!status.Found && status2.Found && status3.Found && output == input1)
{
Console.WriteLine("(5) Success!");
}
else
{
Console.WriteLine("(5) Error!");
}
}
