More error handling improvements.

LorienMan · Nov 26, 2011 · fa5e1b1 · fa5e1b1
1 parent f4f971c
commit fa5e1b1
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Showing 8 changed files with 116 additions and 87 deletions.
diff --git a/Decoder/FIDecoder.m b/Decoder/FIDecoder.m
@@ -4,45 +4,44 @@
 
 @implementation FIDecoder
 
-- (NSError*) errorWithCode: (NSUInteger) errorCode message: (NSString*) message
-{
-    NSDictionary *userInfo = [NSDictionary dictionaryWithObject:message forKey:NSLocalizedDescriptionKey];
-    return [NSError errorWithDomain:FIErrorDomain code:errorCode userInfo:userInfo];
-}
-
 - (FISample*) decodeSampleAtPath: (NSString*) path error: (NSError**) error
 {
-    NSParameterAssert(path);
-
     OSStatus errcode = noErr;
     UInt32 propertySize;
     AudioFileID fileId = 0;
-    NSURL *fileURL = [NSURL fileURLWithPath:path];
     error = error ? error : &(NSError*){ nil };
 
+    if (!path) {
+        *error = [FIError
+            errorWithMessage:@"File not found."
+            code:FIErrorFileReadFailed];
+        return nil;
+    }
+
+    NSURL *fileURL = [NSURL fileURLWithPath:path];
     errcode = AudioFileOpenURL((__bridge CFURLRef) fileURL, kAudioFileReadPermission, 0, &fileId);
     if (errcode) {
-        *error = [self
-            errorWithCode:FIErrorFileReadFailed
-            message:@"Can’t open file."];
+        *error = [FIError
+            errorWithMessage:@"Can’t open file."
+            code:FIErrorFileReadFailed];
         return nil;
     }
 
     AudioStreamBasicDescription fileFormat;
     propertySize = sizeof(fileFormat);
     errcode = AudioFileGetProperty(fileId, kAudioFilePropertyDataFormat, &propertySize, &fileFormat);
     if (errcode) {
-        *error = [self
-            errorWithCode:FIErrorFileFormatReadFailed
-            message:@"Can’t read file format."];
+        *error = [FIError
+            errorWithMessage:@"Can’t read file format."
+            code:FIErrorFileFormatReadFailed];
         AudioFileClose(fileId);
         return nil;
     }
 
     if (fileFormat.mFormatID != kAudioFormatLinearPCM) {
-        *error = [self
-            errorWithCode:FIErrorInvalidFileFormat
-            message:@"Audio format not linear PCM."];
+        *error = [FIError
+            errorWithMessage:@"Audio format not linear PCM."
+            code:FIErrorInvalidFileFormat];
         AudioFileClose(fileId);
         return nil;
     }
@@ -51,9 +50,9 @@ - (FISample*) decodeSampleAtPath: (NSString*) path error: (NSError**) error
     propertySize = sizeof(fileSize);
     errcode = AudioFileGetProperty(fileId, kAudioFilePropertyAudioDataByteCount, &propertySize, &fileSize);
     if (errcode) {
-        *error = [self
-            errorWithCode:FIErrorFileFormatReadFailed
-            message:@"Can’t read audio data byte count."];
+        *error = [FIError
+            errorWithMessage:@"Can’t read audio data byte count."
+            code:FIErrorFileFormatReadFailed];
         AudioFileClose(fileId);
         return nil;
     }
@@ -62,28 +61,28 @@ - (FISample*) decodeSampleAtPath: (NSString*) path error: (NSError**) error
     propertySize = sizeof(sampleLength);
     errcode = AudioFileGetProperty(fileId, kAudioFilePropertyEstimatedDuration, &propertySize, &sampleLength);
     if (errcode) {
-        *error = [self
-            errorWithCode:FIErrorFileFormatReadFailed
-            message:@"Can’t read estimated audio duration."];
+        *error = [FIError
+            errorWithMessage:@"Can’t read estimated audio duration."
+            code:FIErrorFileFormatReadFailed];
         AudioFileClose(fileId);
         return nil;
     }
 
     UInt32 dataSize = (UInt32) fileSize;
     void *data = malloc(dataSize);
     if (!data) {
-        *error = [self
-            errorWithCode:FIErrorMemoryAllocationFailed
-            message:@"Can’t allocate memory for audio data."];
+        *error = [FIError
+            errorWithMessage:@"Can’t allocate memory for audio data."
+            code:FIErrorMemoryAllocationFailed];
         AudioFileClose(fileId);
         return nil;
     }
 
     errcode = AudioFileReadBytes(fileId, false, 0, &dataSize, data);
     if (errcode) {
-        *error = [self
-            errorWithCode:FIErrorFileFormatReadFailed
-            message:@"Can’t read audio data from file."];
+        *error = [FIError
+            errorWithMessage:@"Can’t read audio data from file."
+            code:FIErrorFileFormatReadFailed];
         AudioFileClose(fileId);
         free(data);
         return nil;

diff --git a/Demo/Application.m b/Demo/Application.m
@@ -20,8 +20,8 @@ - (void) applicationDidFinishLaunching: (UIApplication*) application
     [soundEngine activateAudioSessionWithCategory:AVAudioSessionCategoryPlayback];
     [soundEngine openAudioDevice];
 
-    [controller setSitarSound:[soundFactory loadSoundNamed:@"sitar.wav"]];
-    [controller setGunSound:[soundFactory loadSoundNamed:@"shot.wav" maxPolyphony:4]];
+    [controller setSitarSound:[soundFactory loadSoundNamed:@"sitar.wav" error:NULL]];
+    [controller setGunSound:[soundFactory loadSoundNamed:@"shot.wav" maxPolyphony:4 error:NULL]];
 
     [window setRootViewController:controller];
     [window makeKeyAndVisible];

diff --git a/Finch/FIError.h b/Finch/FIError.h
@@ -7,5 +7,12 @@ enum {
     FIErrorInvalidFileFormat,
     FIErrorInvalidNumberOfChannels,
     FIErrorInvalidEndianity,
-    FIErrorInvalidSampleResolution
-};
+    FIErrorInvalidSampleResolution,
+    FIErrorOpenALError
+};
+
+@interface FIError : NSObject
+
++ (id) errorWithMessage: (NSString*) message code: (NSUInteger) errorCode;
+
+@end
diff --git a/Finch/FIError.m b/Finch/FIError.m
@@ -1,3 +1,13 @@
 #import "FIError.h"
 
-NSString *const FIErrorDomain = @"FIErrorDomain";
+NSString *const FIErrorDomain = @"FIErrorDomain";
+
+@implementation FIError
+
++ (id) errorWithMessage: (NSString*) message code: (NSUInteger) errorCode
+{
+    NSDictionary *userInfo = [NSDictionary dictionaryWithObject:message forKey:NSLocalizedDescriptionKey];
+    return [NSError errorWithDomain:FIErrorDomain code:errorCode userInfo:userInfo];
+}
+
+@end
diff --git a/Finch/FIFactory.h b/Finch/FIFactory.h
@@ -9,7 +9,7 @@
 
 - (FISoundEngine*) buildSoundEngine;
 
-- (FISound*) loadSoundNamed: (NSString*) soundName;
-- (FISound*) loadSoundNamed: (NSString*) soundName maxPolyphony: (NSUInteger) voices;
+- (FISound*) loadSoundNamed: (NSString*) soundName error: (NSError**) error;
+- (FISound*) loadSoundNamed: (NSString*) soundName maxPolyphony: (NSUInteger) voices error: (NSError**) error;
 
 @end
diff --git a/Finch/FIFactory.m b/Finch/FIFactory.m
@@ -21,21 +21,18 @@ - (FISoundEngine*) buildSoundEngine
     return engine;
 }
 
-- (FISound*) loadSoundNamed: (NSString*) soundName
+- (FISound*) loadSoundNamed: (NSString*) soundName error: (NSError**) error
 {
     NSString *path = [soundBundle pathForResource:soundName ofType:nil];
-    if (!path) {
-        return nil;
-    }
-    FISample *sample = [decoder decodeSampleAtPath:path error:NULL];
-    return [[FISound alloc] initWithSample:sample error:NULL];
+    FISample *sample = [decoder decodeSampleAtPath:path error:error];
+    return [[FISound alloc] initWithSample:sample error:error];
 }
 
-- (FISound*) loadSoundNamed: (NSString*) soundName maxPolyphony: (NSUInteger) voices
+- (FISound*) loadSoundNamed: (NSString*) soundName maxPolyphony: (NSUInteger) voices error: (NSError**) error
 {
     NSMutableArray *sounds = [NSMutableArray array];
     for (NSUInteger i=0; i<voices; i++) {
-        FISound *voice = [self loadSoundNamed:soundName];
+        FISound *voice = [self loadSoundNamed:soundName error:error];
         if (voice == nil)
             return nil;
         [sounds addObject:voice];

diff --git a/Finch/FIFactoryTests.m b/Finch/FIFactoryTests.m
@@ -11,8 +11,8 @@ - (void) testNonExistentSoundHandling
 {
     FISound *soundA = nil, *soundB = nil;
     STAssertNoThrow({
-        soundA = [factory loadSoundNamed:@"none_such"];
-        soundB = [factory loadSoundNamed:@"none_such" maxPolyphony:2];
+        soundA = [factory loadSoundNamed:@"none_such" error:NULL];
+        soundB = [factory loadSoundNamed:@"none_such" maxPolyphony:2 error:NULL];
     },  @"Loading a non-existent sound does not throw.");
     STAssertNil(soundA, @"Loading a non-existent sound returns nil.");
     STAssertNil(soundB, @"Loading a non-existent revolver sound returns nil.");

diff --git a/Finch/FISound.m b/Finch/FISound.m
@@ -12,80 +12,77 @@ @interface FISound ()
 @implementation FISound
 @synthesize loop, duration, gain, pitch, source, buffer;
 
-// Clears the error flag.
-- (BOOL) checkSuccessOrLog: (NSString*) msg
-{
-    ALenum errcode;
-    if ((errcode = alGetError()) != AL_NO_ERROR) {
-        NSLog(@"%@, error code %x.", msg, errcode);
-        return NO;
-    }
-    return YES;
-}
-
 #pragma mark Initialization
 
-- (BOOL) checkFormatConstaintsForSample: (FISample*) sample error: (NSError**) error
+- (id) initWithSample: (FISample*) sample error: (NSError**) error
 {
+    self = [super init];
     error = error ? error : &(NSError*){ nil };
 
+    if (!sample) {
+        return nil;
+    }
+
     // Check the number of channels
     if ([sample numberOfChannels] != 1 && [sample numberOfChannels] != 2) {
-        *error = [NSError errorWithDomain:FIErrorDomain
-            code:FIErrorInvalidNumberOfChannels userInfo:nil];
-        return NO;
+        *error = [FIError
+            errorWithMessage:@"Invalid number of channels, only mono and stereo supported."
+            code:FIErrorInvalidNumberOfChannels];
+        return nil;
     }
 
     // Check sample resolution
     if ([sample bitsPerChannel] != 8 && [sample bitsPerChannel] != 16) {
-        *error = [NSError errorWithDomain:FIErrorDomain
-            code:FIErrorInvalidSampleResolution userInfo:nil];
-        return NO;
+        *error = [FIError
+            errorWithMessage:@"Invalid sample resolution, only 8-bit and 16-bit samples supported."
+            code:FIErrorInvalidSampleResolution];
+        return nil;
     }
 
     // Check data endianity
     if (![sample hasNativeEndianity]) {
-        *error = [NSError errorWithDomain:FIErrorDomain
-            code:FIErrorInvalidEndianity userInfo:nil];
-        return NO;
-    }
-
-    return YES;
-}
-
-- (id) initWithSample: (FISample*) sample error: (NSError**) error
-{
-    self = [super init];
-
-    if (![self checkFormatConstaintsForSample:sample error:error]) {
+        *error = [FIError
+            errorWithMessage:@"Wrong endianity in audio data."
+            code:FIErrorInvalidEndianity];
         return nil;
     }
 
+    // We need valid OpenAL context to continue
     if (!alcGetCurrentContext()) {
-        NSLog(@"OpenAL context not set, did you initialize Finch?");
+        *error = [FIError
+            errorWithMessage:@"OpenAL context not set, did you initialize Finch?"
+            code:FIErrorOpenALError];
         return nil;
     }
 
     // Allocate OpenAL buffer
     CLEAR_ERROR_FLAG;
     alGenBuffers(1, &buffer);
-    if (![self checkSuccessOrLog:@"Failed to allocate OpenAL buffer"]) {
+    if (alGetError()) {
+        *error = [FIError
+            errorWithMessage:@"Failed to allocate OpenAL buffer."
+            code:FIErrorOpenALError];
         return nil;
     }
 
     // Pass sound data to OpenAL
     CLEAR_ERROR_FLAG;
-    alBufferData(buffer, [sample openALFormat], [[sample data] bytes],
-        [[sample data] length], [sample sampleRate]);
-    if (![self checkSuccessOrLog:@"Failed to fill OpenAL buffers"]) {
+    alBufferData(buffer, [sample openALFormat], [[sample data] bytes], [[sample data] length], [sample sampleRate]);
+    if (alGetError()) {
+        *error = [FIError
+            errorWithMessage:@"Failed to fill OpenAL buffers."
+            code:FIErrorOpenALError];
         return nil;
     }
 
     // Initialize the OpenAL source
     CLEAR_ERROR_FLAG;
     alGenSources(1, &source);
     alSourcei(source, AL_BUFFER, buffer);
-    if (![self checkSuccessOrLog:@"Failed to create OpenAL source"]) {
+    if (alGetError()) {
+        *error = [FIError
+            errorWithMessage:@"Failed to create OpenAL source."
+            code:FIErrorOpenALError];
         return nil;
     }
 
@@ -94,13 +91,32 @@ - (id) initWithSample: (FISample*) sample error: (NSError**) error
     return self;
 }
 
+// Clears the error flag.
+- (BOOL) checkSuccessOrLog: (NSString*) msg
+{
+    ALenum errcode;
+    if ((errcode = alGetError()) != AL_NO_ERROR) {
+        NSLog(@"%@, error code %x.", msg, errcode);
+        return NO;
+    }
+    return YES;
+}
+
 - (void) dealloc
 {
     [self stop];
     CLEAR_ERROR_FLAG;
-    alSourcei(source, AL_BUFFER, DETACH_SOURCE);
-    alDeleteBuffers(1, &buffer), buffer = 0;
-    alDeleteSources(1, &source), source = 0;
+    if (source) {
+        alSourcei(source, AL_BUFFER, DETACH_SOURCE);
+    }
+    if (buffer) {
+        alDeleteBuffers(1, &buffer);
+        buffer = 0;
+    }
+    if (source) {
+        alDeleteSources(1, &source);
+        source = 0;
+    }
     [self checkSuccessOrLog:@"Failed to clean up after sound"];
 }