Legacy Documentclose button

Important: The information in this document is obsolete and should not be used for new development.

Previous Book Contents Book Index Next

Inside Macintosh: Devices /
Chapter 2 - Slot Manager / Slot Manager Reference
Slot Manager Routines / Getting Information From sResources


SGetBlock

You can use the SGetBlock function to obtain a copy of an sBlock data structure pointed to by the offset field of an sResource entry.

FUNCTION SGetBlock (spBlkPtr: SpBlockPtr): OSErr;
spBlkPtr
A pointer to a Slot Manager parameter block.
<--spResultPtrA pointer to a copy of an sBlock data structure (described on page 2-9).
-->spsPointerPtrA pointer to an sResource (described in "The sResource," beginning on page 2-7).
-->spIDSignedByteThe ID of the sResource entry.
XspSizeLongInt 
XspOffsetDataLongInt 
XspByteLanesSignedByte 
XspFlagsSignedByte 

DESCRIPTION
The SGetBlock function returns a copy of the sBlock data structure pointed to by the offset field of an sResource entry.

In the parameter block you point to in the spBlkPtr parameter, you provide a pointer to the sResource in the spsPointer field and specify the ID of the entry in the spID field.

The SGetBlock function allocates a memory buffer, copies the contents of the sBlock data structure into it, and returns a pointer to it in the spResult field. You should dispose of this pointer by using the Memory Manager procedure DisposePtr.

SPECIAL CONSIDERATIONS
The SGetBlock function may alter the values of the spSize, spOffsetData, spByteLanes, and spFlags fields of the parameter block. Your application should not depend on the values returned in these fields.

The SGetBlock function allocates memory; your application should not call this function at interrupt time.

ASSEMBLY-LANGUAGE INFORMATION
The trap macro and routine selector for the SGetBlock function are
Trap macroSelector
_SlotManager$0005

You must set up register D0 with the routine selector and register A0 with the address of the Slot Manager parameter block. When _SlotManager returns, register D0 contains the result code.
Registers on entry
A0Address of the parameter block
D0$0005
Registers on exit
D0Result code

RESULT CODES
noErr0No error
smNoMoresRsrcs-344Requested sResource not found

Previous Book Contents Book Index Next

© Apple Computer, Inc.
3 JUL 1996