OrcLib: Stream: add StreamUtils.h containing generic stream helpers

Author: fabienfl-orc

src/OrcLib/CMakeLists.txt

@@ -584,6 +584,7 @@ set(SRC_STREAM
     "Stream/SpanStreamConcept.h"
     "Stream/Stream.h"
     "Stream/StreamConcept.h"
+    "Stream/StreamUtils.h"
 )
 
 source_group(Stream

src/OrcLib/Filesystem/Ntfs/Compression/WofStreamConcept.h

@@ -14,6 +14,7 @@
 
 #include "Filesystem/Ntfs/Compression/WofChunks.h"
 #include "Stream/SeekDirection.h"
+#include "Stream/StreamUtils.h"
 #include "Utils/MetaPtr.h"
 
 namespace Orc {
@@ -199,7 +200,7 @@ class WofStreamConcept
         fmt::basic_memory_buffer<uint8_t, 8192> buffer;
         buffer.resize(m_chunks.GetChunkTableSize());
 
-        Orc::ReadChunkAt(*m_stream, m_startOffset, buffer, ec);
+        Orc::Stream::ReadChunkAt(*m_stream, m_startOffset, buffer, ec);
         if (ec)
         {
             Log::Debug("Failed to read chunk table [{}]", ec);
@@ -237,7 +238,7 @@ class WofStreamConcept
         // Use 'ReadChunk' to do as many 'Read()' on the stream as necessary to fill the 'chunk' buffer.
         const auto& chunk = m_locations[chunkIndex];
         output.resize(chunk.size);
-        return Orc::ReadChunkAt(*m_stream, chunk.offset, output, ec);
+        return Orc::Stream::ReadChunkAt(*m_stream, chunk.offset, output, ec);
     }
 
     // Decompress a chunk and shift the output to 'uncompressedOffset'. Uses an internal buffer if needed.

src/OrcLib/Stream/BufferStreamConcept.h

@@ -11,7 +11,6 @@
 #include <cstdint>
 #include <system_error>
 
-#include "Stream/Stream.h"
 #include "Stream/SeekDirection.h"
 #include "Utils/BufferView.h"
 #include "Utils/MetaPtr.h"

src/OrcLib/Stream/FileStreamConcept.h

@@ -10,7 +10,8 @@
 
 #include <system_error>
 
-#include "Stream/StreamConcept.h"
+#include "Stream/SeekDirection.h"
+#include "Utils/BufferView.h"
 #include "Utils/Guard.h"
 
 namespace Orc {

src/OrcLib/Stream/StreamConcept.h

@@ -8,20 +8,10 @@
 
 #pragma once
 
-#include <system_error>
-
-#include <gsl/span>
-
-#include "Text/Fmt/Offset.h"
-#include "Log/Log.h"
-#include "Utils/BufferView.h"
-#include "Utils/TypeTraits.h"
-#include "Stream/SeekDirection.h"
-
 namespace Orc {
 
 /*
- * StreamConcept interface
+ * Stream concept
  *
  * class StreamConcept
  * {
@@ -30,174 +20,7 @@ namespace Orc {
  *    size_t Write(BufferView& input, std::error_code& ec);
  *    uint64_t Seek(SeekDirection direction, int64_t value, std::error_code& ec);
  * };
- */
-
-/*!
- * \brief Read 'stream' and shrink output to read size.
- */
-template <typename InputStreamT, typename CharT>
-size_t Read(InputStreamT& stream, gsl::span<CharT> output, std::error_code& ec)
-{
-    gsl::span<uint8_t> span(reinterpret_cast<uint8_t*>(output.data()), output.size() * sizeof(CharT));
-    return stream.Read(span, ec);
-}
-
-/*!
- * \brief Read 'stream' until 'output' is completely filled.
- */
-template <typename InputStreamT, typename CharT>
-size_t ReadChunk(InputStreamT& stream, gsl::span<CharT> output, std::error_code& ec)
-{
-    uint64_t processed = 0;
-
-    while (processed != output.size())
-    {
-        // TODO: subview
-        gsl::span<uint8_t> span(
-            reinterpret_cast<uint8_t*>(output.data() + processed), output.size() * sizeof(CharT) - processed);
-
-        const auto lastReadSize = stream.Read(span, ec);
-        if (ec)
-        {
-            return processed;
-        }
-
-        if (lastReadSize == 0)
-        {
-            Log::Debug("Input stream does not provide enough bytes to fill buffer");
-            ec = std::make_error_code(std::errc::message_size);
-            return processed;
-        }
-
-        processed += lastReadSize;
-    }
-
-    return processed;
-}
-
-/*!
- * \brief Read 'stream' until 'output' is completely filled.
- */
-template <typename InputStreamT, typename ContainerT>
-size_t Read(InputStreamT& stream, ContainerT& output, std::error_code& ec)
-{
-    gsl::span<uint8_t> span(reinterpret_cast<uint8_t*>(output.data()), output.size() * sizeof(ContainerT::value_type));
-
-    size_t processed = stream.Read(span, ec);
-    if (ec)
-    {
-        return processed;
-    }
-
-    output.resize(processed / sizeof(ContainerT::value_type));
-    return processed;
-}
-
-/*!
- * \brief Read 'stream' until 'output' is completely filled.
  *
- * TODO: C++20: use std::is_contiguous_iterator
  */
-template <typename InputStreamT, typename ContainerT>
-size_t ReadChunk(InputStreamT& stream, ContainerT& output, std::error_code& ec)
-{
-    gsl::span<uint8_t> span(reinterpret_cast<uint8_t*>(output.data()), output.size() * sizeof(ContainerT::value_type));
-    return ReadChunk(stream, span, ec);
-}
-
-/*!
- * \brief Read at specified position the available bytes and store them in container of type ContainerT
- *
- * TODO: C++20: use std::is_contiguous_iterator
- */
-template <typename InputStreamT, typename ContainerT>
-size_t ReadAt(InputStreamT& stream, uint64_t offset, ContainerT& output, std::error_code& ec)
-{
-    stream.Seek(SeekDirection::kBegin, offset, ec);
-    if (ec)
-    {
-        Log::Debug("Failed to seek to position: {} [{}]", Traits::Offset(offset), ec);
-        return 0;
-    }
-
-    return Read(stream, output, ec);
-}
-
-/*!
- * \brief Read at specified position in 'stream' until 'output' is completely filled.
- *
- * TODO: C++20: use std::is_contiguous_iterator
- */
-template <typename InputStreamT, typename ContainerT>
-size_t ReadChunkAt(InputStreamT& stream, uint64_t offset, ContainerT& output, std::error_code& ec)
-{
-    stream.Seek(SeekDirection::kBegin, offset, ec);
-    if (ec)
-    {
-        Log::Debug("Failed to seek to position: {} [{}]", Traits::Offset(offset), ec);
-        return 0;
-    }
-
-    gsl::span<uint8_t> span(reinterpret_cast<uint8_t*>(output.data()), output.size() * sizeof(ContainerT::value_type));
-    return ReadChunk(stream, span, ec);
-}
-
-/*!
- * \brief Read at specified position in 'stream' until 'output' is completely filled.
- *
- * TODO: C++20: use std::is_contiguous_iterator
- */
-template <typename InputStreamT, typename CharT>
-size_t
-ReadChunkAt(InputStreamT& stream, uint64_t offset, size_t chunkSizeCb, gsl::span<CharT> output, std::error_code& ec)
-{
-    stream.Seek(SeekDirection::kBegin, offset, ec);
-    if (ec)
-    {
-        Log::Debug("Failed to seek to position: {} [{}]", Traits::Offset(offset), ec);
-        return 0;
-    }
-
-    assert(chunkSizeCb < output.size() * sizeof(CharT) && "Buffer 'output' overflow");
-
-    gsl::span<uint8_t> span(reinterpret_cast<uint8_t*>(output.data()), chunkSizeCb);
-    return ReadChunk(stream, span, ec);
-}
-
-/*!
- * \brief Fill an item of type 'T' and fail if there is not enough data to read.
- */
-template <typename InputStreamT, typename ItemT>
-void ReadItem(InputStreamT& stream, ItemT& output, std::error_code& ec)
-{
-    uint64_t processed = stream.Read(gsl::span<uint8_t>(reinterpret_cast<uint8_t*>(&output), sizeof(output)), ec);
-    if (ec)
-    {
-        return;
-    }
-
-    if (processed != sizeof(output))
-    {
-        ec = std::make_error_code(std::errc::interrupted);
-        Log::Debug("Failed to read expected size ({}/{})", processed, sizeof(ItemT));
-        return;
-    }
-}
-
-/*!
- * \brief Fill an item of type 'T' and fail if there is not enough data to read.
- */
-template <typename InputStreamT, typename ItemT>
-void ReadItemAt(InputStreamT& stream, uint64_t offset, ItemT& output, std::error_code& ec)
-{
-    stream.Seek(SeekDirection::kBegin, offset, ec);
-    if (ec)
-    {
-        Log::Debug("Failed to seek to position: {} [{}]", Traits::Offset(offset), ec);
-        return;
-    }
-
-    ReadItem(stream, output, ec);
-}
 
 }  // namespace Orc