void extractBLKX()

in dmg/io.c [303:391]
76 lines of code
13 McCabe index (conditional complexity)

void extractBLKX(AbstractFile* in, AbstractFile* out, BLKXTable* blkx) {
	unsigned char* inBuffer;
	unsigned char* outBuffer;
	unsigned char zero;
	size_t bufferSize;
	size_t have;
	size_t expectedSize;
	off_t initialOffset;
	int i;
	int ret;
	uint32_t type;

	bufferSize = SECTOR_SIZE * blkx->decompressBufferRequested;
	ASSERT(inBuffer = (unsigned char*) malloc(bufferSize), "malloc");

	initialOffset =	out->tell(out);
	ASSERT(initialOffset != -1, "ftello");

	zero = 0;

	for(i = 0; i < blkx->blocksRunCount; i++) {
		ASSERT(in->seek(in, blkx->dataStart + blkx->runs[i].compOffset) == 0, "fseeko");
		ASSERT(out->seek(out, initialOffset + (blkx->runs[i].sectorStart * SECTOR_SIZE)) == 0, "mSeek");

		if(blkx->runs[i].sectorCount > 0) {
			ASSERT(out->seek(out, initialOffset + (blkx->runs[i].sectorStart + blkx->runs[i].sectorCount) * SECTOR_SIZE - 1) == 0, "mSeek");
			ASSERT(out->write(out, &zero, 1) == 1, "mWrite");
			ASSERT(out->seek(out, initialOffset + (blkx->runs[i].sectorStart * SECTOR_SIZE)) == 0, "mSeek");
		}

		if(blkx->runs[i].type == BLOCK_TERMINATOR) {
			break;
		}

		if( blkx->runs[i].compLength == 0) {
			continue;
		}

		printf("run %d: start=%" PRId64 " sectors=%" PRId64 ", length=%" PRId64 ", fileOffset=0x%" PRIx64 "\n", i, initialOffset + (blkx->runs[i].sectorStart * SECTOR_SIZE), blkx->runs[i].sectorCount, blkx->runs[i].compLength, blkx->runs[i].compOffset);



		switch(blkx->runs[i].type) {
			case BLOCK_RAW:
				if(blkx->runs[i].compLength > bufferSize) {
					uint64_t left = blkx->runs[i].compLength;
					void* pageBuffer = malloc(DEFAULT_BUFFER_SIZE);
					while(left > 0) {
						size_t thisRead;
						if(left > DEFAULT_BUFFER_SIZE) {
							thisRead = DEFAULT_BUFFER_SIZE;
						} else {
							thisRead = left;
						}
						ASSERT((have = in->read(in, pageBuffer, thisRead)) == thisRead, "fread");
						ASSERT(out->write(out, pageBuffer, have) == have, "mWrite");
						left -= have;
					}
					free(pageBuffer);
				} else {
					ASSERT((have = in->read(in, inBuffer, blkx->runs[i].compLength)) == blkx->runs[i].compLength, "fread");
					ASSERT(out->write(out, inBuffer, have) == have, "mWrite");
				}
				break;
			case BLOCK_IGNORE:
				break;
			case BLOCK_COMMENT:
				break;
			case BLOCK_TERMINATOR:
				break;
			default:
				type = blkx->runs[i].type;
				if (compressionBlockTypeSupported(type) != 0) {
					fprintf(stderr, "Unsupported block type %#08x\n", type);
					exit(1);
				}

				expectedSize = blkx->runs[i].sectorCount * SECTOR_SIZE;
				ASSERT(outBuffer = (unsigned char*)malloc(expectedSize), "malloc");
				ASSERT(in->read(in, inBuffer, blkx->runs[i].compLength) == blkx->runs[i].compLength, "fread");
				ASSERT(decompressRun(type, inBuffer, blkx->runs[i].compLength, outBuffer, expectedSize) == 0,
					"decompression failed");
				ASSERT(out->write(out, outBuffer, expectedSize) == expectedSize, "mWrite");
				free(outBuffer);
		}
	}

	free(inBuffer);
}