diff options
| -rw-r--r-- | lib/posix/posix.nim | 19 |
1 files changed, 17 insertions, 2 deletions
diff --git a/lib/posix/posix.nim b/lib/posix/posix.nim index aee9308a6..07652c64d 100644 --- a/lib/posix/posix.nim +++ b/lib/posix/posix.nim @@ -198,9 +198,24 @@ proc posix_fadvise*(a1: cint, a2, a3: Off, a4: cint): cint {. proc ftruncate*(a1: cint, a2: Off): cint {.importc, header: "<unistd.h>".} when defined(osx): # 2001 POSIX evidently does not concern Apple + type FStore {.importc: "fstore_t", header: "<fcntl.h>", bycopy.} = object + fst_flags: uint32 ## IN: flags word + fst_posmode: cint ## IN: indicates offset field + fst_offset, ## IN: start of the region + fst_length, ## IN: size of the region + fst_bytesalloc: Off ## OUT: number of bytes allocated + var F_PEOFPOSMODE {.importc, header: "<fcntl.h>".}: cint + var F_ALLOCATEALL {.importc, header: "<fcntl.h>".}: uint32 + var F_PREALLOCATE {.importc, header: "<fcntl.h>".}: cint proc posix_fallocate*(a1: cint, a2, a3: Off): cint = - ftruncate(a1, a2 + a3) # Set size to off + len, max offset -else: # TODO: Use fcntl(fd, F_PREALLOCATE, ..) above + var fst = FStore(fst_flags: F_ALLOCATEALL, fst_posmode: F_PEOFPOSMODE, + fst_offset: a2, fst_length: a3) + # Must also call ftruncate to match what POSIX does. Unlike posix_fallocate, + # this can shrink files. Could guard w/getFileSize, but caller likely knows + # present size & has no good reason to call this unless it is growing. + if fcntl(a1, F_PREALLOCATE, fst.addr) != cint(-1): ftruncate(a1, a2 + a3) + else: cint(-1) +else: proc posix_fallocate*(a1: cint, a2, a3: Off): cint {. importc, header: "<fcntl.h>".} |