HELP for file operation

[bomz]

Thank's I read it. But it's not very quickly

[donkey]

Thank's I read it. But it's not very quickly

Yeah, its a bit hard to read, but in my opinion you're better off using FILE_FLAG_WRITE_THROUGH if you don't want the data cached during a write operation, not sure why you picked FILE_FLAG_NO_BUFFERING, I assume you needed it for your applications purposes.

[bomz]

if the sector size is 512 bytes, an application can request reads and writes of 512, 1,024, 1,536, or 2,048 bytes, but not of 335, 981, or 7,171 bytes...........33554432=32 mb


in other case there is not only any writing but reading too

FILE_FLAG_WRITE_THROUGH cause the same result as NO_BUFFERING

VirtualAlloc and Heap - the same result in all flag combination

[donkey]

if the sector size is 512 bytes, an application can request reads and writes of 512, 1,024, 1,536, or 2,048 bytes, but not of 335, 981, or 7,171 bytes...........33554432=32 mb


in other case there is not only any writing but reading too

FILE_FLAG_WRITE_THROUGH cause the same result as NO_BUFFERING

No, the 32MB buffer size you are using may be correct however the write request on the only write (if the file is under 32MB) is for a portion of that and will cause the write to fail, the read succeeds because the buffer size is the complete 32MB. For example if ReadFile reads 1057 bytes that is what your write request is, the actual size of the buffer is not important, your request is not aligned because you are telling WriteFile the size of the buffer is 1057 bytes. The way your program is written it will always fail unless the actual file size is a multiple of the sector size, which would be common in many executable files but in others would not be.

Edgar

[bomz]

but how it cause copying AVI files and not copy HLP files?

[donkey]

but how it cause copying AVI files and not copy HLP files?

Again check the file size. Is the AVI a multiple of sector size ? Is the HLP file ? When you subtract 3MB is the remainder a multiple of sector size ? The flag you selected is a specialty flag that requires you only use buffers and write sizes within very strict parameters.

[bomz]

yes you right the reason is in the size

[bomz]

THANKS!

[donkey]

My pleasure bomz.