issue-2086: introduce IFileIOServiceProvider

cloud/blockstore/libs/service_local/file_io_service_provider.cpp

@@ -0,0 +1,115 @@
+#include "file_io_service_provider.h"
+
+#include <cloud/storage/core/libs/common/file_io_service.h>
+
+#include <util/generic/algorithm.h>
+#include <util/generic/string.h>
+#include <util/generic/vector.h>
+
+namespace NCloud::NBlockStore::NServer {
+
+namespace {
+
+////////////////////////////////////////////////////////////////////////////////
+
+class TFileIOServiceProvider final
+    : public IFileIOServiceProvider
+{
+private:
+    const ui32 PathsPerServices;
+    std::function<IFileIOServicePtr()> Factory;
+
+    TVector<std::pair<TString, size_t>> PathToFileIOIndex;
+    TVector<IFileIOServicePtr> FileIOs;
+
+public:
+    explicit TFileIOServiceProvider(
+            ui32 pathsPerServices,
+            std::function<IFileIOServicePtr()> factory)
+        : PathsPerServices{Max(pathsPerServices, 1U)}
+        , Factory(std::move(factory))
+    {}
+
+    void Start() override
+    {}
+
+    void Stop() override
+    {
+        for (auto& fileIO: FileIOs) {
+            fileIO->Stop();
+        }
+    }
+
+    IFileIOServicePtr CreateFileIOService(TStringBuf filePath) override
+    {
+        if (auto* p = FindIfPtr(
+                PathToFileIOIndex,
+                [=](const auto& p) { return p.first == filePath; }))
+        {
+            return FileIOs[p->second];
+        }
+
+        if ((PathToFileIOIndex.size() + 1) > PathsPerServices * FileIOs.size())
+        {
+            auto service = Factory();
+            Y_DEBUG_ABORT_UNLESS(service);
+            service->Start();
+            FileIOs.push_back(service);
+        }
+
+        PathToFileIOIndex.emplace_back(filePath, FileIOs.size() - 1);
+
+        return FileIOs.back();
+    }
+};
+
+////////////////////////////////////////////////////////////////////////////////
+
+struct TFileIOServiceProviderStub final
+    : IFileIOServiceProvider
+{
+    IFileIOServicePtr FileIO;
+
+    explicit TFileIOServiceProviderStub(
+            IFileIOServicePtr fileIO)
+        : FileIO{std::move(fileIO)}
+    {}
+
+    void Start() override
+    {
+        FileIO->Start();
+    }
+
+    void Stop() override
+    {
+        FileIO->Stop();
+    }
+
+    IFileIOServicePtr CreateFileIOService(TStringBuf filePath) override
+    {
+        Y_UNUSED(filePath);
+
+        return FileIO;
+    }
+};
+
+}   // namespace
+
+////////////////////////////////////////////////////////////////////////////////
+
+IFileIOServiceProviderPtr CreateFileIOServiceProviderStub(
+    IFileIOServicePtr fileIO)
+{
+    return std::make_shared<TFileIOServiceProviderStub>(std::move(fileIO));
+}
+
+IFileIOServiceProviderPtr CreateFileIOServiceProvider(
+    ui32 filePathsPerServices,
+    std::function<IFileIOServicePtr()> factory)
+{
+    return std::make_shared<TFileIOServiceProvider>(
+        filePathsPerServices,
+        std::move(factory));
+}
+
+}   // namespace NCloud::NBlockStore::NServer

cloud/blockstore/libs/service_local/file_io_service_provider.h

@@ -0,0 +1,31 @@
+#pragma once
+
+#include "public.h"
+
+#include <cloud/storage/core/libs/common/public.h>
+#include <cloud/storage/core/libs/common/startable.h>
+
+#include <util/generic/strbuf.h>
+
+#include <functional>
+
+namespace NCloud::NBlockStore::NServer {
+
+////////////////////////////////////////////////////////////////////////////////
+
+struct IFileIOServiceProvider
+    : IStartable
+{
+    virtual IFileIOServicePtr CreateFileIOService(TStringBuf filePath) = 0;
+};
+
+////////////////////////////////////////////////////////////////////////////////
+
+IFileIOServiceProviderPtr CreateFileIOServiceProviderStub(
+    IFileIOServicePtr fileIO);
+
+IFileIOServiceProviderPtr CreateFileIOServiceProvider(
+    ui32 filePathsPerServices,
+    std::function<IFileIOServicePtr()> factory);
+
+}   // namespace NCloud::NBlockStore::NServer