source: trunk/Sparkle/SUPipedUnarchiver.m @ 1046

//
//  SUPipedUnarchiver.m
//  Sparkle
//
//  Created by Andy Matuschak on 6/16/08.
//  Copyright 2008 Andy Matuschak. All rights reserved.
//

#import "SUPipedUnarchiver.h"
#import "SUUnarchiver_Private.h"

@implementation SUPipedUnarchiver

+ (SEL)_selectorConformingToTypeOfPath:(NSString *)path
{
    static NSDictionary *typeSelectorDictionary;
    if (!typeSelectorDictionary)
        typeSelectorDictionary = [[NSDictionary dictionaryWithObjectsAndKeys:@"_extractZIP", @".zip", @"_extractTAR", @".tar",
                                   @"_extractTGZ", @".tar.gz", @"_extractTGZ", @".tgz",
                                   @"_extractTBZ", @".tar.bz2", @"_extractTBZ", @".tbz", nil] retain];

    NSString *lastPathComponent = [path lastPathComponent];
    NSEnumerator *typeEnumerator = [typeSelectorDictionary keyEnumerator];
    id currentType;
    while ((currentType = [typeEnumerator nextObject]))
    {
        if ([currentType length] > [lastPathComponent length]) continue;
        if ([[lastPathComponent substringFromIndex:[lastPathComponent length] - [currentType length]] isEqualToString:currentType])
            return NSSelectorFromString([typeSelectorDictionary objectForKey:currentType]);
    }
    return NULL;
}

- (void)start
{
    [NSThread detachNewThreadSelector:[[self class] _selectorConformingToTypeOfPath:archivePath] toTarget:self withObject:nil];
}

+ (BOOL)_canUnarchivePath:(NSString *)path
{
    return ([self _selectorConformingToTypeOfPath:path] != nil);
}

// This method abstracts the types that use a command line tool piping data from stdin.
- (void)_extractArchivePipingDataToCommand:(NSString *)command
{
    NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init];
    FILE *fp = NULL, *cmdFP = NULL;
    
    // Get the file size.
    NSNumber *fs = [[[NSFileManager defaultManager] fileAttributesAtPath:archivePath traverseLink:NO] objectForKey:NSFileSize];
    if (fs == nil) goto reportError;
    
    // Thank you, Allan Odgaard!
    // (who wrote the following extraction alg.)
    fp = fopen([archivePath fileSystemRepresentation], "r");
    if (!fp) goto reportError;
    
    setenv("DESTINATION", [[archivePath stringByDeletingLastPathComponent] fileSystemRepresentation], 1);
    cmdFP = popen([command fileSystemRepresentation], "w");
    if (!cmdFP) goto reportError;
    
    char buf[32*1024];
    long len;
    while((len = fread(buf, 1, 32*1024, fp)))
    {               
        fwrite(buf, 1, len, cmdFP);
        [self performSelectorOnMainThread:@selector(_notifyDelegateOfExtractedLength:) withObject:[NSNumber numberWithLong:len] waitUntilDone:NO];
    }
    pclose(cmdFP);
    
    [self performSelectorOnMainThread:@selector(_notifyDelegateOfSuccess) withObject:nil waitUntilDone:NO];
    goto finally;
    
reportError:
    [self performSelectorOnMainThread:@selector(_notifyDelegateOfFailure) withObject:nil waitUntilDone:NO];
    
finally:
    if (fp)
        fclose(fp);
    [pool drain];
}

- (void)_extractTAR
{
    return [self _extractArchivePipingDataToCommand:@"tar -xC \"$DESTINATION\""];
}

- (void)_extractTGZ
{
    return [self _extractArchivePipingDataToCommand:@"tar -zxC \"$DESTINATION\""];
}

- (void)_extractTBZ
{
    return [self _extractArchivePipingDataToCommand:@"tar -jxC \"$DESTINATION\""];
}

- (void)_extractZIP
{
    return [self _extractArchivePipingDataToCommand:@"ditto -x -k - \"$DESTINATION\""];
}

+ (void)load
{
    [self _registerImplementation:self];
}

@end