diff options
Diffstat (limited to 'ghc/lib/std/cbits/writeFile.c')
-rw-r--r-- | ghc/lib/std/cbits/writeFile.c | 130 |
1 files changed, 130 insertions, 0 deletions
diff --git a/ghc/lib/std/cbits/writeFile.c b/ghc/lib/std/cbits/writeFile.c new file mode 100644 index 0000000000..a54ba6567d --- /dev/null +++ b/ghc/lib/std/cbits/writeFile.c @@ -0,0 +1,130 @@ +/* + * (c) The GRASP/AQUA Project, Glasgow University, 1994-1998 + * + * $Id: writeFile.c,v 1.3 1998/12/02 13:28:07 simonm Exp $ + * + * hPutStr Runtime Support + */ + +#include "Rts.h" +#include "stgio.h" + +StgInt +writeFileObject(ptr, bytes) +StgForeignPtr ptr; +StgInt bytes; +{ + int rc=0; + IOFileObject* fo = (IOFileObject*)ptr; + + char *p = (char *) fo->buf; + + /* If we've got a r/w file object in our hand, flush the + (input) buffer contents first. + */ + if ( FILEOBJ_READABLE(fo) && FILEOBJ_JUST_READ(fo) ) { + fo->flags = (fo->flags & ~FILEOBJ_RW_READ) | FILEOBJ_RW_WRITE; + rc = flushReadBuffer(ptr); + if (rc < 0) return rc; + } + + return (writeBuffer(ptr, bytes)); +} + +StgInt +writeBuffer(ptr, bytes) +StgForeignPtr ptr; +StgInt bytes; +{ + int count, rc=0; + IOFileObject* fo = (IOFileObject*)ptr; + + char *p = (char *) fo->buf; + + /* Disallow short writes */ + if (bytes == 0 || fo->buf == NULL) + return 0; + + if ( fo->flags & FILEOBJ_NONBLOCKING_IO && inputReady(ptr,0) != 1 ) + return FILEOBJ_BLOCKED_WRITE; + + while ((count = write(fo->fd, fo->buf, bytes)) < bytes) { + if (errno != EINTR) { + cvtErrno(); + stdErrno(); + return -1; + } + bytes -= count; + p += count; + } + /* Signal that we've emptied the buffer */ + fo->bufWPtr=0; + return 0; +} + + +StgInt +writeBuf(ptr, buf, len) +StgForeignPtr ptr; +StgAddr buf; +StgInt len; +{ + IOFileObject* fo = (IOFileObject*)ptr; + int count; + int rc = 0; + char *p = (char *) buf; + + if (len == 0 ) + return 0; + + /* First of all, check if we do need to flush the buffer .. */ + /* Note - in the case of line buffering, we do not currently check + whether we need to flush buffer due to line terminators in the + buffer we're outputting */ + if ( fo->buf != NULL && /* buffered and */ + (fo->bufWPtr + len < (fo->bufSize)) /* there's room */ + ) { + /* Block copying is likely to be cheaper than, flush, followed by write */ + memcpy(((char*)fo->buf + fo->bufWPtr), buf, len); + fo->bufWPtr += len; + return 0; + } + /* If we do overflow, flush current contents of the buffer and + directly output the chunk. + (no attempt at splitting up the chunk is currently made) + */ + if ( fo->buf != NULL && /* buffered and */ + (fo->bufWPtr + len >= (fo->bufSize)) /* there's not room */ + ) { + /* Flush buffer */ + rc = writeFileObject(ptr, fo->bufWPtr); + /* ToDo: undo buffer fill if we're blocking.. */ + } + + if (rc != 0) { + return rc; + } + + if ( fo->flags & FILEOBJ_NONBLOCKING_IO && inputReady(ptr,0) != 1 ) + return FILEOBJ_BLOCKED_WRITE; + + /* Disallow short writes */ + while ((count = write(fo->fd, (char *)buf, (int)len)) < len) { + if (errno != EINTR) { + cvtErrno(); + stdErrno(); + return -1; + } + len -= count; + p += count; + } + + return 0; +} + +StgInt +writeBufBA(ptr, buf, len) + StgForeignPtr ptr; +StgByteArray buf; +StgInt len; +{ return (writeBuf(ptr,(StgAddr)buf, len)); } |