mirror of https://github.com/acidanthera/audk.git
f72fd9616e
The COMP shell command compares two files byte for byte. In order to retrieve the bytes to compare, it currently invokes gEfiShellProtocol->ReadFile() on both files, using a single-byte buffer every time. This is very inefficient; the underlying EFI_FILE_PROTOCOL.Read() function may be costly. Read both file operands in chunks of "PcdShellFileOperationSize" bytes. Draw bytes for comparison from the internal read-ahead buffers. Some ad-hoc measurements on my laptop, using OVMF, and the 4KB default of "PcdShellFileOperationSize": - When comparing two identical 1MB files that are served by EnhancedFatDxe on top of VirtioScsiDxe, this patch brings no noticeable improvement; the comparison completes in <1s both before and after. - When comparing two identical 1MB files served by VirtioFsDxe, the comparison time improves from 2 minutes 25 seconds to <1s. Cc: Philippe Mathieu-Daudé <philmd@redhat.com> Cc: Ray Ni <ray.ni@intel.com> Cc: Zhichao Gao <zhichao.gao@intel.com> Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=3123 Signed-off-by: Laszlo Ersek <lersek@redhat.com> Reviewed-by: Zhichao Gao <zhichao.gao@intel.com> Message-Id: <20210113085453.10168-2-lersek@redhat.com> Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com> |
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| Application | ||
| DynamicCommand | ||
| Include | ||
| Library | ||
| ShellPkg.ci.yaml | ||
| ShellPkg.dec | ||
| ShellPkg.dsc | ||