BufferingAudioFormatReader: Return failure from read() in more cases

read() now returns failure in the case of a read timeout, or if
reading any block failed.

modules/juce_audio_formats/format/juce_AudioFormatReader.cpp

@@ -115,7 +115,7 @@ bool AudioFormatReader::read (int* const* destChannels,
     return true;
 }
 
-static void readChannels (AudioFormatReader& reader, int** chans, AudioBuffer<float>* buffer,
+static bool readChannels (AudioFormatReader& reader, int** chans, AudioBuffer<float>* buffer,
                           int startSample, int numSamples, int64 readerStartSample, int numTargetChannels,
                           bool convertToFloat)
 {
@@ -123,13 +123,16 @@ static void readChannels (AudioFormatReader& reader, int** chans, AudioBuffer<fl
         chans[j] = reinterpret_cast<int*> (buffer->getWritePointer (j, startSample));
 
     chans[numTargetChannels] = nullptr;
-    reader.read (chans, numTargetChannels, readerStartSample, numSamples, true);
+
+    const bool success = reader.read (chans, numTargetChannels, readerStartSample, numSamples, true);
 
     if (convertToFloat)
         convertFixedToFloat (chans, numTargetChannels, numSamples);
+
+    return success;
 }
 
-void AudioFormatReader::read (AudioBuffer<float>* buffer,
+bool AudioFormatReader::read (AudioBuffer<float>* buffer,
                               int startSample,
                               int numSamples,
                               int64 readerStartSample,
@@ -139,58 +142,61 @@ void AudioFormatReader::read (AudioBuffer<float>* buffer,
     jassert (buffer != nullptr);
     jassert (startSample >= 0 && startSample + numSamples <= buffer->getNumSamples());
 
-    if (numSamples > 0)
-    {
-        auto numTargetChannels = buffer->getNumChannels();
-
-        if (numTargetChannels <= 2)
-        {
-            int* dests[2] = { reinterpret_cast<int*> (buffer->getWritePointer (0, startSample)),
-                              reinterpret_cast<int*> (numTargetChannels > 1 ? buffer->getWritePointer (1, startSample) : nullptr) };
-            int* chans[3] = {};
-
-            if (useReaderLeftChan == useReaderRightChan)
-            {
-                chans[0] = dests[0];
+    if (numSamples <= 0)
+        return true;
 
-                if (numChannels > 1)
-                    chans[1] = dests[1];
-            }
-            else if (useReaderLeftChan || (numChannels == 1))
-            {
-                chans[0] = dests[0];
-            }
-            else if (useReaderRightChan)
-            {
-                chans[1] = dests[0];
-            }
+    auto numTargetChannels = buffer->getNumChannels();
 
-            read (chans, 2, readerStartSample, numSamples, true);
+    if (numTargetChannels <= 2)
+    {
+        int* dests[2] = { reinterpret_cast<int*> (buffer->getWritePointer (0, startSample)),
+                          reinterpret_cast<int*> (numTargetChannels > 1 ? buffer->getWritePointer (1, startSample) : nullptr) };
+        int* chans[3] = {};
 
-            // if the target's stereo and the source is mono, dupe the first channel..
-            if (numTargetChannels > 1
-                && (chans[0] == nullptr || chans[1] == nullptr)
-                && (dests[0] != nullptr && dests[1] != nullptr))
-            {
-                memcpy (dests[1], dests[0], (size_t) numSamples * sizeof (float));
-            }
+        if (useReaderLeftChan == useReaderRightChan)
+        {
+            chans[0] = dests[0];
 
-            if (! usesFloatingPointData)
-                convertFixedToFloat (dests, 2, numSamples);
+            if (numChannels > 1)
+                chans[1] = dests[1];
         }
-        else if (numTargetChannels <= 64)
+        else if (useReaderLeftChan || (numChannels == 1))
         {
-            int* chans[65];
-            readChannels (*this, chans, buffer, startSample, numSamples,
-                          readerStartSample, numTargetChannels, ! usesFloatingPointData);
+            chans[0] = dests[0];
         }
-        else
+        else if (useReaderRightChan)
+        {
+            chans[1] = dests[0];
+        }
+
+        if (! read (chans, 2, readerStartSample, numSamples, true))
+            return false;
+
+        // if the target's stereo and the source is mono, dupe the first channel..
+        if (numTargetChannels > 1
+            && (chans[0] == nullptr || chans[1] == nullptr)
+            && (dests[0] != nullptr && dests[1] != nullptr))
         {
-            HeapBlock<int*> chans (numTargetChannels + 1);
-            readChannels (*this, chans, buffer, startSample, numSamples,
-                          readerStartSample, numTargetChannels, ! usesFloatingPointData);
+            memcpy (dests[1], dests[0], (size_t) numSamples * sizeof (float));
         }
+
+        if (! usesFloatingPointData)
+            convertFixedToFloat (dests, 2, numSamples);
+
+        return true;
     }
+
+    if (numTargetChannels <= 64)
+    {
+        int* chans[65];
+        return readChannels (*this, chans, buffer, startSample, numSamples,
+                             readerStartSample, numTargetChannels, ! usesFloatingPointData);
+    }
+
+    HeapBlock<int*> chans (numTargetChannels + 1);
+
+    return readChannels (*this, chans, buffer, startSample, numSamples,
+                         readerStartSample, numTargetChannels, ! usesFloatingPointData);
 }
 
 void AudioFormatReader::readMaxLevels (int64 startSampleInFile, int64 numSamples,

modules/juce_audio_formats/format/juce_AudioFormatReader.h

@@ -132,8 +132,12 @@ public:
         the buffer's floating-point format, and will try to intelligently
         cope with mismatches between the number of channels in the reader
         and the buffer.
+
+        @returns    true if the operation succeeded, false if there was an error. Note
+                    that reading sections of data beyond the extent of the stream isn't an
+                    error - the reader should just return zeros for these regions
     */
-    void read (AudioBuffer<float>* buffer,
+    bool read (AudioBuffer<float>* buffer,
                int startSampleInDestBuffer,
                int numSamples,
                int64 readerStartSample,

modules/juce_audio_formats/format/juce_BufferingAudioFormatReader.cpp

@@ -56,6 +56,8 @@ bool BufferingAudioReader::readSamples (int** destSamples, int numDestChannels,
     const ScopedLock sl (lock);
     nextReadPosition = startSampleInFile;
 
+    bool allSamplesRead = true;
+
     while (numSamples > 0)
     {
         if (auto block = getBlockContaining (startSampleInFile))
@@ -79,6 +81,8 @@ bool BufferingAudioReader::readSamples (int** destSamples, int numDestChannels,
             startOffsetInDestBuffer += numToDo;
             startSampleInFile += numToDo;
             numSamples -= numToDo;
+
+            allSamplesRead = allSamplesRead && block->allSamplesRead;
         }
         else
         {
@@ -88,6 +92,7 @@ bool BufferingAudioReader::readSamples (int** destSamples, int numDestChannels,
                     if (auto* dest = (float*) destSamples[j])
                         FloatVectorOperations::clear (dest + startOffsetInDestBuffer, numSamples);
 
+                allSamplesRead = false;
                 break;
             }
             else
@@ -98,14 +103,14 @@ bool BufferingAudioReader::readSamples (int** destSamples, int numDestChannels,
         }
     }
 
-    return true;
+    return allSamplesRead;
 }
 
 BufferingAudioReader::BufferedBlock::BufferedBlock (AudioFormatReader& reader, int64 pos, int numSamples)
     : range (pos, pos + numSamples),
-      buffer ((int) reader.numChannels, numSamples)
+      buffer ((int) reader.numChannels, numSamples),
+      allSamplesRead (reader.read (&buffer, 0, numSamples, pos, true, true))
 {
-    reader.read (&buffer, 0, numSamples, pos, true, true);
 }
 
 BufferingAudioReader::BufferedBlock* BufferingAudioReader::getBlockContaining (int64 pos) const noexcept

modules/juce_audio_formats/format/juce_BufferingAudioFormatReader.h

@@ -66,6 +66,7 @@ private:
 
         Range<int64> range;
         AudioBuffer<float> buffer;
+        bool allSamplesRead = false;
     };
 
     int useTimeSlice() override;