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juce_BufferedInputStream.cpp
/*
==============================================================================
This file is part of the JUCE library.
Copyright (c) 2022 - Raw Material Software Limited
JUCE is an open source library subject to commercial or open-source
licensing.
The code included in this file is provided under the terms of the ISC license
http://www.isc.org/downloads/software-support-policy/isc-license. 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.
JUCE IS PROVIDED "AS IS" WITHOUT ANY WARRANTY, AND ALL WARRANTIES, WHETHER
EXPRESSED OR IMPLIED, INCLUDING MERCHANTABILITY AND FITNESS FOR PURPOSE, ARE
DISCLAIMED.
==============================================================================
*/
namespace juce
{
static int calcBufferStreamBufferSize (int requestedSize, InputStream* source) noexcept
{
// You need to supply a real stream when creating a BufferedInputStream
jassert (source != nullptr);
requestedSize = jmax (256, requestedSize);
auto sourceSize = source->getTotalLength();
if (sourceSize >= 0 && sourceSize < requestedSize)
return jmax (32, (int) sourceSize);
return requestedSize;
}
//==============================================================================
BufferedInputStream::BufferedInputStream (InputStream* sourceStream, int size, bool takeOwnership)
: source (sourceStream, takeOwnership),
bufferedRange (sourceStream->getPosition(), sourceStream->getPosition()),
position (bufferedRange.getStart()),
bufferLength (calcBufferStreamBufferSize (size, sourceStream))
{
buffer.malloc (bufferLength);
}
BufferedInputStream::BufferedInputStream (InputStream& sourceStream, int size)
: BufferedInputStream (&sourceStream, size, false)
{
}
BufferedInputStream::~BufferedInputStream() = default;
//==============================================================================
char BufferedInputStream::peekByte()
{
if (! ensureBuffered())
return 0;
return position < lastReadPos ? buffer[(int) (position - bufferedRange.getStart())] : 0;
}
int64 BufferedInputStream::getTotalLength()
{
return source->getTotalLength();
}
int64 BufferedInputStream::getPosition()
{
return position;
}
bool BufferedInputStream::setPosition (int64 newPosition)
{
position = jmax ((int64) 0, newPosition);
return true;
}
bool BufferedInputStream::isExhausted()
{
return position >= lastReadPos && source->isExhausted();
}
bool BufferedInputStream::ensureBuffered()
{
auto bufferEndOverlap = lastReadPos - bufferOverlap;
if (position < bufferedRange.getStart() || position >= bufferEndOverlap)
{
int bytesRead = 0;
if (position < lastReadPos
&& position >= bufferEndOverlap
&& position >= bufferedRange.getStart())
{
auto bytesToKeep = (int) (lastReadPos - position);
memmove (buffer, buffer + (int) (position - bufferedRange.getStart()), (size_t) bytesToKeep);
bytesRead = source->read (buffer + bytesToKeep,
(int) (bufferLength - bytesToKeep));
if (bytesRead < 0)
return false;
lastReadPos += bytesRead;
bytesRead += bytesToKeep;
}
else
{
if (! source->setPosition (position))
return false;
bytesRead = (int) source->read (buffer, (size_t) bufferLength);
if (bytesRead < 0)
return false;
lastReadPos = position + bytesRead;
}
bufferedRange = Range<int64> (position, lastReadPos);
while (bytesRead < bufferLength)
buffer[bytesRead++] = 0;
}
return true;
}
int BufferedInputStream::read (void* destBuffer, const int maxBytesToRead)
{
const auto initialPosition = position;
const auto getBufferedRange = [this] { return bufferedRange; };
const auto readFromReservoir = [this, &destBuffer, &initialPosition] (const Range<int64> rangeToRead)
{
memcpy (static_cast<char*> (destBuffer) + (rangeToRead.getStart() - initialPosition),
buffer + (rangeToRead.getStart() - bufferedRange.getStart()),
(size_t) rangeToRead.getLength());
};
const auto fillReservoir = [this] (int64 requestedStart)
{
position = requestedStart;
ensureBuffered();
};
const auto remaining = Reservoir::doBufferedRead (Range<int64> (position, position + maxBytesToRead),
getBufferedRange,
readFromReservoir,
fillReservoir);
const auto bytesRead = maxBytesToRead - remaining.getLength();
position = remaining.getStart();
return (int) bytesRead;
}
String BufferedInputStream::readString()
{
if (position >= bufferedRange.getStart()
&& position < lastReadPos)
{
auto maxChars = (int) (lastReadPos - position);
auto* src = buffer + (int) (position - bufferedRange.getStart());
for (int i = 0; i < maxChars; ++i)
{
if (src[i] == 0)
{
position += i + 1;
return String::fromUTF8 (src, i);
}
}
}
return InputStream::readString();
}
//==============================================================================
//==============================================================================
#if JUCE_UNIT_TESTS
struct BufferedInputStreamTests final : public UnitTest
{
template <typename Fn, size_t... Ix, typename Values>
static void applyImpl (Fn&& fn, std::index_sequence<Ix...>, Values&& values)
{
fn (std::get<Ix> (values)...);
}
template <typename Fn, typename... Values>
static void apply (Fn&& fn, std::tuple<Values...> values)
{
applyImpl (fn, std::make_index_sequence<sizeof... (Values)>(), values);
}
template <typename Fn, typename Values>
static void allCombinationsImpl (Fn&& fn, Values&& values)
{
apply (fn, values);
}
template <typename Fn, typename Values, typename Range, typename... Ranges>
static void allCombinationsImpl (Fn&& fn, Values&& values, Range&& range, Ranges&&... ranges)
{
for (auto& item : range)
allCombinationsImpl (fn, std::tuple_cat (values, std::tie (item)), ranges...);
}
template <typename Fn, typename... Ranges>
static void allCombinations (Fn&& fn, Ranges&&... ranges)
{
allCombinationsImpl (fn, std::tie(), ranges...);
}
BufferedInputStreamTests()
: UnitTest ("BufferedInputStream", UnitTestCategories::streams)
{}
void runTest() override
{
const MemoryBlock testBufferA ("abcdefghijklmnopqrstuvwxyz", 26);
const auto testBufferB = [&]
{
MemoryBlock mb { 8192 };
auto r = getRandom();
std::for_each (mb.begin(), mb.end(), [&] (char& item)
{
item = (char) r.nextInt (std::numeric_limits<char>::max());
});
return mb;
}();
const MemoryBlock buffers[] { testBufferA, testBufferB };
const int readSizes[] { 3, 10, 50 };
const bool shouldPeek[] { false, true };
const auto runTest = [this] (const MemoryBlock& data, const int readSize, const bool peek)
{
MemoryInputStream mi (data, true);
BufferedInputStream stream (mi, jmin (200, (int) data.getSize()));
beginTest ("Read");
expectEquals (stream.getPosition(), (int64) 0);
expectEquals (stream.getTotalLength(), (int64) data.getSize());
expectEquals (stream.getNumBytesRemaining(), stream.getTotalLength());
expect (! stream.isExhausted());
size_t numBytesRead = 0;
MemoryBlock readBuffer (data.getSize());
while (numBytesRead < data.getSize())
{
if (peek)
expectEquals (stream.peekByte(), *(char*) (data.begin() + numBytesRead));
const auto startingPos = numBytesRead;
numBytesRead += (size_t) stream.read (readBuffer.begin() + numBytesRead, readSize);
expect (std::equal (readBuffer.begin() + startingPos,
readBuffer.begin() + numBytesRead,
data.begin() + startingPos,
data.begin() + numBytesRead));
expectEquals (stream.getPosition(), (int64) numBytesRead);
expectEquals (stream.getNumBytesRemaining(), (int64) (data.getSize() - numBytesRead));
expect (stream.isExhausted() == (numBytesRead == data.getSize()));
}
expectEquals (stream.getPosition(), (int64) data.getSize());
expectEquals (stream.getNumBytesRemaining(), (int64) 0);
expect (stream.isExhausted());
expect (readBuffer == data);
beginTest ("Skip");
stream.setPosition (0);
expectEquals (stream.getPosition(), (int64) 0);
expectEquals (stream.getTotalLength(), (int64) data.getSize());
expectEquals (stream.getNumBytesRemaining(), stream.getTotalLength());
expect (! stream.isExhausted());
numBytesRead = 0;
const int numBytesToSkip = 5;
while (numBytesRead < data.getSize())
{
expectEquals (stream.peekByte(), *(char*) (data.begin() + numBytesRead));
stream.skipNextBytes (numBytesToSkip);
numBytesRead += numBytesToSkip;
numBytesRead = std::min (numBytesRead, data.getSize());
expectEquals (stream.getPosition(), (int64) numBytesRead);
expectEquals (stream.getNumBytesRemaining(), (int64) (data.getSize() - numBytesRead));
expect (stream.isExhausted() == (numBytesRead == data.getSize()));
}
expectEquals (stream.getPosition(), (int64) data.getSize());
expectEquals (stream.getNumBytesRemaining(), (int64) 0);
expect (stream.isExhausted());
};
allCombinations (runTest, buffers, readSizes, shouldPeek);
}
};
static BufferedInputStreamTests bufferedInputStreamTests;
#endif
} // namespace juce
juce::BufferedInputStream::~BufferedInputStream
~BufferedInputStream() override
juce::BufferedInputStream::BufferedInputStream
BufferedInputStream(InputStream *sourceStream, int bufferSize, bool deleteSourceWhenDestroyed)
Definition juce_BufferedInputStream.cpp:41
juce::BufferedInputStream::getPosition
int64 getPosition() override
Definition juce_BufferedInputStream.cpp:71
juce::BufferedInputStream::peekByte
char peekByte()
Definition juce_BufferedInputStream.cpp:58
juce::BufferedInputStream::isExhausted
bool isExhausted() override
Definition juce_BufferedInputStream.cpp:82
juce::BufferedInputStream::readString
String readString() override
Definition juce_BufferedInputStream.cpp:162
juce::BufferedInputStream::read
int read(void *destBuffer, int maxBytesToRead) override
Definition juce_BufferedInputStream.cpp:133
juce::BufferedInputStream::getTotalLength
int64 getTotalLength() override
Definition juce_BufferedInputStream.cpp:66
juce::BufferedInputStream::setPosition
bool setPosition(int64 newPosition) override
Definition juce_BufferedInputStream.cpp:76
juce::InputStream
Definition juce_InputStream.h:37
juce::InputStream::readString
virtual String readString()
Definition juce_InputStream.cpp:182
juce::Range
Definition juce_Range.h:40
juce::Range::getStart
constexpr ValueType getStart() const noexcept
Definition juce_Range.h:80
juce::String
Definition juce_String.h:53
juce::String::fromUTF8
static String fromUTF8(const char *utf8buffer, int bufferSizeBytes=-1)
Definition juce_String.cpp:2125
juce::UnitTest
Definition juce_UnitTest.h:70
juce::Reservoir::doBufferedRead
static Range< Index > doBufferedRead(Range< Index > rangeToRead, GetBufferedRange &&getBufferedRange, ReadFromReservoir &&readFromReservoir, FillReservoir &&fillReservoir)
Definition juce_Reservoir.h:69