WritePartialResource

Write part of a resource to disk

#include <Resources.h> Resource Manager

void WritePartialResource(theResource, offset, buffer, count);

Handle theResource ; 4-byte ResType; resource type to get

long offset ; byte offset value

Ptr buffer ; source buffer

long count ; number of bytes in buffer

The WritePartialResource procedure writes part of a resource to disk,

which allows you to work with small portions of large resources. The resource

is specified by the parameter theResource from the offset parameter, which is

in bytes, through the number of bytes given by the value of the count

parameter. The Resource Manager writes to the resource from the buffer

you indicate with the buffer parameter. You are responsible for the memory

management of this buffer. Call the ResError function to check for errors.

If the disk or the file is locked, the ResError function returns the

appropriate file system error. If you try to write past the end of a resource,

the Resource Manager attempts to enlarge the resource. ResError returns

the writingPastEnd result code if the attempt is successful. If it cannot enlarge

the resource, ResError returns the appropriate file system error. If you

pass an invalid value in the offset parameter, ResError returns the

inputOutOfBounds result code.

If the resource is in memory when you call the WritePartialResource

procedure, the Resource Manager tries to write the resource. If the attempt

is successful, ResError returns resourceInMemory and does not update the

copy in memory. You should be aware that in this situation, the copy in

memory is different from the resource on disk. If the attempt to write the

resource to disk is not successful, ResError returns the appropriate error.

When using partial resource routines, you should call the SetResLoad

procedure specifying FALSE for its load parameter before you call the

GetResource function. The SetResLoad procedure prevents the

Resource Manager from reading the entire resource into memory. Be sure

to restore the normal state of the SetResLoad procedure after you call the

Returns: an Error Code. It will be one of:

dskFulErr (-34) Disk full

resourceInMemory (-188) Resource already in memory

writingPastEnd (-189) Writing past end of file

inputOutOfBounds (-190) Offset or count out of bounds

Referenced by (6):