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CcReadAhead macro
The CcReadAhead macro performs read-ahead (also called "lazy read") on a cached file.
Syntax
VOID CcReadAhead(
[in] PFILE_OBJECT FileObject,
[in] PLARGE_INTEGER FileOffset,
[in] ULONG Length
);
Parameters
FileObject [in]
Pointer to a file object for the cached file on which read-ahead is to be performed.FileOffset [in]
Pointer to a variable that specifies the starting byte offset within the cached file where the last read occurred.Length [in]
Length in bytes of the range that was last read.
Return value
None
Remarks
The CcReadAhead macro is a wrapper for CcScheduleReadAhead that calls CcScheduleReadAhead only if Length >= 256. Measurements have shown that calling CcScheduleReadAhead for smaller reads actually decreases performance.
CcReadAhead can only be called after a successful call to CcCopyRead, CcFastCopyRead, or CcMdlRead.
Requirements
Target platform |
Desktop |
Header |
Ntifs.h (include Ntifs.h) |