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ADC Home > Reference Library > Reference > Audio > Carbon > Disc Recording Framework Reference
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DRFileDataProduction |
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Informal protocol describing methods implemented by the file data producer.
This protocol defines those methods that a file data producer instance must implement. A file data producer is the object that resposible for providing the file data to the burn engine on request
calculateSizeOfFile:fork:estimating: |
Calculates the size of the specified fork of a file.
- (uint64_t) calculateSizeOfFile:(DRFile*)file fork:(DRFileFork)fork estimating:(BOOL)estimate;
fileforkestimateThe length of the file's fork.
This method may be sent at any time after the file object has been instantiated.
Requests that the recevier calculate the byte size of a file's fork (for instance, data fork or resource fork).
If estimate is YES, you are being asked for an estimate of the final
fork size, perhaps to provide an estimate of the track size, and do not
have to be exact. Estimates should err on the high side; it's better to
overestimate than underestimate. An estimate call may be made at any time.
If estimate is NO, you are being asked for
the actual fork size, to be used in the burn. This call is only
made in the burn phase.
cleanupFileAfterBurn: |
Cleanup the file object once the burn is complete.
- (void) cleanupFileAfterBurn:(DRFile*)file;
fileSent to the receiver after the burn completes. This would be an appropriate place to close files, or do any other teardown work needed. This message will always be sent regardless of whether the burn succeeded or failed
prepareFileForBurn: |
Prepare the file object for burning.
- (BOOL) prepareFileForBurn:(DRFile*)file;
fileYES if the burn should proceed.
Sent to the recevier before the burn begins. This would be an appropriate
method to open files, or do any other prep work needed. The disc's entire
hierarchy is completely in place and can be queried if needed.
After this call, the burn's content is locked down, and you should be
able to respond to the calculateSizeOfFile:fork:estimating: messages with exact values.
prepareFileForVerification: |
Prepare the file object for verification.
- (BOOL) prepareFileForVerification:(DRFile*)file;
fileYES to indicate that the verification should proceed and NO to indicate a failure occurred.
Sent during the burn (after production and before the cleanupFileAfterBurn: message) to indicate that verification is about to begin. Now would be a good time to rewind to the start of the file, reset state machines, or do whatever else is needed to prepare to produce again.
produceFile:fork:intoBuffer:length:atAddress:blockSize: |
Produces the specified fork contents for burning.
- (uint32_t) produceFile:(DRFile*)file fork:(DRFileFork)fork intoBuffer:(char*)buffer length:(uint32_t)bufferLength atAddress:(uint64_t)address blockSize:(uint32_t)blockSize;
fileforkbufferbufferLengthaddressblockSizeThe number of bytes produced.
Sent during the burn (after the prepareFileForBurn message) requesting that the receiver
produce the specified fork contents.
The recevier should fill up the buffer passed in as full as possible
and then return control to the caller. While burning keeping the drive's buffer full is
of utmost importance, so you should not perform lengthy operations or block for data in this method.
This method should return the number of bytes actually in the buffer or 0 to indicate that there
was an error producing the data.
You may be asked to produce twice, once during the actual burn and once during
verification depending on the verification type of the track.
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