Blob.cpp

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/*
 * SPDX-License-Identifier: GPL-2.0-or-later
 * SPDX-FileName: Blob.cpp
 * SPDX-FileContributor: Dmitry Vedenko
 */
 
#include "Blob.h"
 
#include <algorithm>
#include <cassert>
#include <utility>
 
#include <sqlite3.h>
 
namespace audacity::sqlite
{
Blob::Blob(sqlite3_blob* blob) noexcept
    : mBlob { blob }
{
   assert(mBlob != nullptr);
}
 
Blob::~Blob() noexcept
{
   if (mBlob != nullptr)
   {
      sqlite3_blob_close(mBlob);
      mBlob = nullptr;
   }
}
 
Blob::Blob(Blob&& rhs) noexcept
{
   *this = std::move(rhs);
}
 
Blob& Blob::operator=(Blob&& rhs) noexcept
{
   std::swap(mBlob, rhs.mBlob);
   return *this;
}
 
int64_t Blob::Size() const noexcept
{
   if (mBlob == nullptr)
      return 0;
 
   return sqlite3_blob_bytes(mBlob);
}
 
int64_t
Blob::Read(void* buffer, int64_t offset, int64_t bufferSize) const noexcept
{
   if (mBlob == nullptr)
      return 0;
 
   const int readSize = std::min<int>(bufferSize, Size() - offset);
 
   if (bufferSize <= 0)
      return 0;
 
    if (
      SQLITE_OK !=
      sqlite3_blob_read(mBlob, buffer, readSize, static_cast<int>(offset)))
      return 0;
 
   return readSize;
}
 
int64_t
Blob::Write(const void* buffer, int64_t offset, int64_t bufferSize) noexcept
{
   if (mBlob == nullptr)
      return 0;
 
   const int writeSize = std::min<int>(bufferSize, Size() - offset);
 
   if (bufferSize <= 0)
      return 0;
 
   if (
      SQLITE_OK !=
      sqlite3_blob_write(mBlob, buffer, writeSize, static_cast<int>(offset)))
      return 0;
 
   return writeSize;
}
 
} // namespace audacity::sqlite