Add RandomAccessFile

modules/beast_core/files/beast_RandomAccessFile.cpp

@@ -0,0 +1,214 @@
+//------------------------------------------------------------------------------
+/*
+    This file is part of Beast: https://github.com/vinniefalco/Beast
+    Copyright 2013, Vinnie Falco <vinnie.falco@gmail.com>
+
+    Portions of this file are from JUCE.
+    Copyright (c) 2013 - Raw Material Software Ltd.
+    Please visit http://www.juce.com
+
+    Permission to use, copy, modify, and/or distribute this software for any
+    purpose  with  or without fee is hereby granted, provided that the above
+    copyright notice and this permission notice appear in all copies.
+
+    THE  SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+    WITH  REGARD  TO  THIS  SOFTWARE  INCLUDING  ALL  IMPLIED  WARRANTIES  OF
+    MERCHANTABILITY  AND  FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+    ANY  SPECIAL ,  DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+    WHATSOEVER  RESULTING  FROM  LOSS  OF USE, DATA OR PROFITS, WHETHER IN AN
+    ACTION  OF  CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+    OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+*/
+//==============================================================================
+
+RandomAccessFile::RandomAccessFile (int bufferSizeToUse) noexcept
+    : fileHandle (nullptr)
+    , currentPosition (0)
+    , bufferSize (bufferSizeToUse)
+    , bytesInBuffer (0)
+    , writeBuffer (bmax (bufferSizeToUse, 16)) // enforce minimum size of 16
+{
+}
+
+RandomAccessFile::~RandomAccessFile ()
+{
+    close ();
+}
+
+Result RandomAccessFile::open (File const& path, Mode mode)
+{
+    close ();
+
+    return nativeOpen (path, mode);
+}
+
+void RandomAccessFile::close ()
+{
+    if (isOpen ())
+    {
+        flushBuffer ();
+        nativeFlush ();
+        nativeClose ();
+    }
+}
+
+Result RandomAccessFile::setPosition (FileOffset newPosition)
+{
+    Result result (Result::ok ());
+
+    if (newPosition != currentPosition)
+    {
+        flushBuffer ();
+
+        result = nativeSetPosition (newPosition);
+    }
+
+    return result;
+}
+
+Result RandomAccessFile::read (void* buffer, ByteCount numBytes, ByteCount* pActualAmount)
+{
+    return nativeRead (buffer, numBytes, pActualAmount);
+}
+
+Result RandomAccessFile::write (const void* data, ByteCount numBytes, ByteCount* pActualAmount)
+{
+    bassert (data != nullptr && ((ssize_t) numBytes) >= 0);
+
+    Result result (Result::ok ());
+
+    ByteCount amountWritten = 0;
+
+    if (bytesInBuffer + numBytes < bufferSize)
+    {
+        memcpy (writeBuffer + bytesInBuffer, data, numBytes);
+        bytesInBuffer += numBytes;
+        currentPosition += numBytes;
+    }
+    else
+    {
+        result = flushBuffer ();
+
+        if (result.wasOk ())
+        {
+            if (numBytes < bufferSize)
+            {
+                bassert (bytesInBuffer == 0);
+
+                memcpy (writeBuffer + bytesInBuffer, data, numBytes);
+                bytesInBuffer += numBytes;
+                currentPosition += numBytes;
+            }
+            else
+            {
+                ByteCount bytesWritten;
+
+                result = nativeWrite (data, numBytes, &bytesWritten);
+
+                if (result.wasOk ())
+                    currentPosition += bytesWritten;
+            }
+        }
+    }
+
+    if (pActualAmount != nullptr)
+        *pActualAmount = amountWritten;
+
+    return result;
+}
+
+Result RandomAccessFile::truncate ()
+{
+    Result result = flush ();
+
+    if (result.wasOk ())
+        result = nativeTruncate ();
+
+    return result;
+}
+
+Result RandomAccessFile::flush ()
+{
+    Result result = flushBuffer ();
+
+    if (result.wasOk ())
+        result = nativeFlush ();
+
+    return result;
+}
+
+Result RandomAccessFile::flushBuffer ()
+{
+    bassert (isOpen ());
+
+    Result result (Result::ok ());
+
+    if (bytesInBuffer > 0)
+    {
+        result = nativeWrite (writeBuffer, bytesInBuffer);
+        bytesInBuffer = 0;
+    }
+
+    return result;
+}
+
+//------------------------------------------------------------------------------
+
+class RandomAccessFileTests : public UnitTest
+{
+public:
+    RandomAccessFileTests () : UnitTest ("RandomAccessFile")
+    {
+    }
+
+    struct Payload
+    {
+        Payload (int maxBytes)
+            : bufferSize (maxBytes)
+            , data (maxBytes)
+        {
+        }
+
+        // Create a pseudo-random payload
+        void generate (int64 seedValue) noexcept
+        {
+            Random r (seedValue);
+
+            bytes = 1 + r.nextInt (bufferSize);
+
+            bassert (bytes >= 1 && bytes <= bufferSize);
+
+            for (int i = 0; i < bytes; ++i)
+                data [i] = static_cast <unsigned char> (r.nextInt ());
+        }
+
+        bool operator== (Payload const& other) const noexcept
+        {
+            if (bytes == other.bytes)
+            {
+                return memcmp (data.getData (), other.data.getData (), bytes) == 0;
+            }
+            else
+            {
+                return false;
+            }
+        }
+
+        int const bufferSize;
+        int bytes;
+        HeapBlock <char> data;
+    };
+
+
+    void runTest ()
+    {
+        Result result = file.open (File::createTempFile ("tests"), RandomAccessFile::readWrite);
+
+        expect (result.wasOk (), "Should be ok");
+    }
+
+private:
+    RandomAccessFile file;
+};
+
+static RandomAccessFileTests randomAccessFileTests;