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CcScheduleReadAhead function (ntifs.h)
The CcScheduleReadAhead routine performs read-ahead (also called "lazy read") on a cached file. CcScheduleReadAhead should never be called directly. The CcReadAhead macro should be called instead.
Syntax
VOID CcScheduleReadAhead(
[in] PFILE_OBJECT FileObject,
[in] PLARGE_INTEGER FileOffset,
[in] ULONG Length
);
Parameters
[in] FileObject
Pointer to a file object for the file on which read-ahead is to be performed.
[in] FileOffset
Pointer to a variable that specifies the starting byte offset within the cached file where the last read occurred.
[in] Length
Length in bytes of the range that was last read.
Return value
None
Remarks
The CcReadAhead macro is a wrapper for CcScheduleReadAhead. It calls CcScheduleReadAhead only if Length >= 256. Measurements have shown that calling CcScheduleReadAhead for smaller reads actually decreases performance.
CcReadAhead and CcScheduleReadAhead can only be called after a successful call to CcCopyRead, CcFastCopyRead, or CcMdlRead.
Requirements
| Requirement | Value |
|---|---|
| Target Platform | Universal |
| Header | ntifs.h (include Ntifs.h) |
| Library | NtosKrnl.lib |
| DLL | NtosKrnl.exe |
See also
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