[project @ 2001-05-18 16:54:04 by simonmar]

I/O library rewrite
-------------------

This commit replaces the old C/Haskell I/O implementation with a new
Haskell-only one using the new FFI & hsc2hs.

main points:

   - lots of code deleted: we're about 3000 lines of C lighter,
     but the amount of Haskell code is about the same.

   - performance is ok: some operations are faster, others are
     slower.  There's still some tuning to do, though.

   - the new library is designed to handle read/write streams
     much better: a read/write stream gets a special kind of
     handle internally called a "DuplexHandle", which actually
     contains two separate handles, one for writing and one for
     reading.  The upshot is that you can do simultaneous reading
     and writing to/from a socket or FIFO without any locking
     problems.  The effect is similar to calling socketToHandle
     twice, except that finalization works properly (creating
     two separate Handles could lead to the socket being closed
     too early when one of the Handles is GC'd).

   - hConnectTo and withHandleFor are gone (no one responded to
     my mail on GHC users, but we can always bring 'em back if
     necessary).

   - I made a half-hearted attempt at keeping the system-specific
     code in one place: see PrelPosix.hsc.

   - I've rearranged the I/O tests and added lots more.
     ghc/tests/lib/IO now contains Haskell 98-only IO tests,
     ghc/test/lib/{IOExts, Directory, Time} now contain tests for
     the relevant libraries.  I haven't quite finished in here yet,
     the IO tests work but the others don't yet.

   - I haven't done anything about Unicode yet, but now we can
     start to discuss what needs doing here.  The new library
     is using MutableByteArrays for its buffers because that
     turned out to be a *lot* easier (and quicker) than malloc'd
     buffers - I hope this won't cause trouble for unicode
     translations though.

WARNING: Windows users refrain from updating until we've had a chance
to fix any issues that arise.

Testing: the basic H98 stuff has been pretty thoroughly tested, but
the new duplex handle stuff is still a little green.

1 files changed, 0 insertions, 357 deletions

diff --git a/ghc/lib/std/cbits/readFile.c b/ghc/lib/std/cbits/readFile.c
deleted file mode 100644
index 8393d071c3..0000000000
--- a/ghc/lib/std/cbits/readFile.c
+++ /dev/null
@@ -1,357 +0,0 @@
-/* 
- * (c) The GRASP/AQUA Project, Glasgow University, 1994-1998
- *
- * $Id: readFile.c,v 1.15 2000/04/12 17:33:16 simonmar Exp $
- *
- * hGetContents Runtime Support
- */
-
-#include "Rts.h"
-#include "stgio.h"
-
-#if defined(HAVE_WINSOCK_H) && !defined(__CYGWIN__) && !defined(__CYGWIN32__)
-#define USE_WINSOCK
-#endif
-
-#ifdef USE_WINSOCK
-#include <winsock.h>
-#endif
-
-#define EOT 4
-
-/* Filling up a (block-buffered) buffer, that
-   is completely empty. */
-StgInt
-readBlock(StgForeignPtr ptr)
-{
-    IOFileObject* fo = (IOFileObject*)ptr;
-    int count,rc=0;
-    int fd;
-
-    /* Check if someone hasn't zapped us */
-    if ( fo == NULL || fo->fd == -1 )
-       return -2;
-
-    fd = fo->fd;
-
-    if ( FILEOBJ_IS_EOF(fo) ) {
-	ghc_errtype = ERR_EOF;
-	ghc_errstr = "";
-	return -1;
-    }
-
-    /* Weird case: buffering has suddenly been turned off.
-       Return non-std value and deal with this case on the Haskell side.
-    */
-    if ( FILEOBJ_UNBUFFERED(fo) ) {
-        return -3;
-    }
-
-    /* if input stream is connect to an output stream, flush this one first. */
-    if ( fo->connectedTo != NULL   &&
-         fo->connectedTo->fd != -1 &&
-         (fo->connectedTo->flags & FILEOBJ_WRITE)
-       ) {
-       rc = flushFile((StgForeignPtr)fo->connectedTo);
-    }
-    if (rc < 0) return (rc == FILEOBJ_BLOCKED_WRITE ? FILEOBJ_BLOCKED_CONN_WRITE : rc);
-
-    /* RW object: flush the (output) buffer first. */
-    if ( FILEOBJ_WRITEABLE(fo) && FILEOBJ_JUST_WRITTEN(fo) && FILEOBJ_NEEDS_FLUSHING(fo) ) {
-        rc = flushBuffer(ptr);
-	if (rc < 0) return rc;
-    }
-    fo->flags = (fo->flags & ~FILEOBJ_RW_WRITE) | FILEOBJ_RW_READ;
-
-    /* return the unread parts of the file buffer..*/
-    if ( fo->flags & FILEOBJ_READ && 
-    	 fo->bufRPtr > 0 	  &&
-	 fo->bufWPtr > fo->bufRPtr ) {
-	count = fo->bufWPtr - fo->bufRPtr;
-        fo->bufRPtr=0;
-        return count;
-    }
-
-#if 0
-    fprintf(stderr, "rb: %d %d %d\n", fo->bufRPtr, fo->bufWPtr, fo->bufSize);
-#endif
-
-    while ((count =
-	     (
-#ifdef USE_WINSOCK
-	       fo->flags & FILEOBJ_WINSOCK ?
-	         recv(fd, fo->buf, fo->bufSize, 0) :
-	         read(fd, fo->buf, fo->bufSize))) <= 0 ) {
-#else
-	         read(fd, fo->buf, fo->bufSize))) <= 0 ) {
-#endif
-	if ( count == 0 ) {
-            FILEOBJ_SET_EOF(fo);
-	    ghc_errtype = ERR_EOF;
-	    ghc_errstr = "";
-	    return -1;
-	} else if ( count == -1 && errno == EAGAIN) {
-	    errno = 0;
-	    return FILEOBJ_BLOCKED_READ;
-	} else if ( count == -1 && errno != EINTR) {
-	    cvtErrno();
-	    stdErrno();
-	    return -1;
-	}
-    }
-    fo->bufWPtr = count;
-    fo->bufRPtr = 0;
-    return count;
-}
-
-/* Filling up a (block-buffered) buffer of length len */
-
-/* readChunk(FileObjet *, void *, int)
- * returns:
- *  -1                             error
- *  -2                             object closed
- *  FILEOBJ_BLOCKED_CONN_WRITE     blocking while flushing
- *                                 buffer of connected handle.
- *  FILEOBJ_BLOCKED_READ           didn't read anything; would block
- *  n, where n > 0                 read n bytes into buffer.
- *  0				   EOF has been reached
- */
-
-StgInt
-readChunk(StgForeignPtr ptr, StgAddr buf, StgInt off, StgInt len)
-{
-    IOFileObject* fo = (IOFileObject*)ptr;
-    int count, rc=0, total_count=0;
-    int fd;
-    char* p;
-
-    /* Check if someone hasn't zapped us */
-    if ( fo == NULL )
-       return -2;
-
-    fd = fo->fd;
-
-    if ( fd == -1 ) /* File has been closed for us */
-       return -2;
-
-    if ( FILEOBJ_IS_EOF(fo) ) {
-        return 0;
-    }
-
-    /* if input stream is connect to an output stream, flush it first */
-    if ( fo->connectedTo != NULL   &&
-         fo->connectedTo->fd != -1 &&
-         (fo->connectedTo->flags & FILEOBJ_WRITE)
-       ) {
-       rc = flushFile((StgForeignPtr)fo->connectedTo);
-    }
-    if (rc < 0) return (rc == FILEOBJ_BLOCKED_WRITE ? FILEOBJ_BLOCKED_CONN_WRITE : rc);
-
-    /* RW object: flush the (output) buffer first. */
-    if ( FILEOBJ_WRITEABLE(fo) && FILEOBJ_JUST_WRITTEN(fo) && FILEOBJ_NEEDS_FLUSHING(fo) ) {
-        rc = flushBuffer(ptr);
-	if (rc < 0) return rc;
-    }
-    fo->flags = (fo->flags & ~FILEOBJ_RW_WRITE) | FILEOBJ_RW_READ;
-
-    p = buf+off;
-
-    /* copy the unread parts of the file buffer..*/
-    if ( FILEOBJ_READABLE(fo) && 
-    	 fo->bufRPtr > 0      &&
-	 fo->bufWPtr >= fo->bufRPtr ) {
-
-        if (fo->bufWPtr - fo->bufRPtr >= len) {
-            /* buffer has enough data to fulfill the request */
-	    memcpy(buf, fo->buf + fo->bufRPtr, len);
-            fo->bufRPtr += len;
-            return len;
-        } else {
-            /* can only partially fulfill the request from the buffer */
-            count = fo->bufWPtr - fo->bufRPtr;
-	    memcpy(buf, fo->buf + fo->bufRPtr, count);
-            fo->bufWPtr=0;
-	    fo->bufRPtr=0;
-            len -= count;
-            p += count;
-            total_count = count;
-        }
-    }
-
-    while ((count =
-             (
-#ifdef USE_WINSOCK
-	       fo->flags & FILEOBJ_WINSOCK ?
-	         recv(fd, p, len, 0) :
-	         read(fd, p, len))) <= 0 ) {
-#else
-	         read(fd, p, len))) <= 0 ) {
-#endif
-        /* EOF */
-	if ( count == 0 ) {
-            FILEOBJ_SET_EOF(fo);
-            return total_count;
-	}
-
-        /* Blocking */
-	else if ( count == -1 && errno == EAGAIN) {
-	    errno = 0;
-            if (total_count > 0) 
-               return total_count; /* partial read */
-	    else
-	       return FILEOBJ_BLOCKED_READ;
-	}
-
-        /* Error */
-	else if ( count == -1 && errno != EINTR) {
-	    cvtErrno();
-	    stdErrno();
-	    return -1;
-        }
-    }
-
-    total_count += count;
-    return total_count;
-}
-
-/*
-  readLine() tries to fill the buffer up with a line of chars, returning
-  the length of the resulting line. 
-  
-  Users of readLine() should immediately afterwards copy out the line
-  from the buffer.
-
-*/
-
-StgInt
-readLine(StgForeignPtr ptr)
-{
-    IOFileObject* fo = (IOFileObject*)ptr;
-    int rc=0, count;
-
-    /* Check if someone hasn't zapped us */
-    if ( fo == NULL || fo->fd == -1 )
-       return -2;
-
-    if ( FILEOBJ_IS_EOF(fo) ) {
-	ghc_errtype = ERR_EOF;
-	ghc_errstr = "";
-	return -1;
-    }
-
-    /* Weird case: buffering has been turned off.
-       Return non-std value and deal with this case on the Haskell side.
-    */
-    if ( FILEOBJ_UNBUFFERED(fo) ) {
-        return -3;
-    }
-
-    /* if input stream is connect to an output stream, flush it first */
-    if ( fo->connectedTo != NULL   &&
-         fo->connectedTo->fd != -1 &&
-         (fo->connectedTo->flags & FILEOBJ_WRITE)
-       ) {
-       rc = flushFile((StgForeignPtr)fo->connectedTo);
-    }
-    if (rc < 0) return (rc == FILEOBJ_BLOCKED_WRITE ? FILEOBJ_BLOCKED_CONN_WRITE : rc);
-
-    /* RW object: flush the (output) buffer first. */
-    if ( FILEOBJ_WRITEABLE(fo) && FILEOBJ_JUST_WRITTEN(fo) ) {
-        rc = flushBuffer(ptr);
-	if (rc < 0) return rc;
-    }
-    fo->flags = (fo->flags & ~FILEOBJ_RW_WRITE) | FILEOBJ_RW_READ;
-
-    if ( fo->bufRPtr < 0 || fo->bufRPtr >= fo->bufWPtr ) { /* Buffer is empty */
-        fo->bufRPtr=0; 
-	fo->bufWPtr=0;
-        rc = fill_up_line_buffer(fo);
-        if (rc < 0) return rc;
-    }
-
-    while (1) {
-       unsigned char* s1 = memchr((unsigned char *)fo->buf+fo->bufRPtr, '\n', fo->bufWPtr - fo->bufRPtr);
-       if (s1 != NULL ) {  /* Found one */
-	  /* Note: we *don't* zero terminate the line */
-	  count = s1 - ((unsigned char*)fo->buf + fo->bufRPtr) + 1;
-	  fo->bufRPtr += count;
-          return count;
-       } else {
-          /* Just return partial line */
-	  count = fo->bufWPtr - fo->bufRPtr;
-	  fo->bufRPtr += count;
-          return count;
-       }
-    }
-
-}
-
-StgInt
-readChar(StgForeignPtr ptr)
-{
-    IOFileObject* fo= (IOFileObject*)ptr;
-    int count,rc=0;
-    unsigned char c;
-
-    /* Check if someone hasn't zapped us */
-    if ( fo == NULL || fo->fd == -1)
-       return -2;
-
-    if ( FILEOBJ_IS_EOF(fo) ) {
-	ghc_errtype = ERR_EOF;
-	ghc_errstr = "";
-	return -1;
-    }
-
-    /* Buffering has been changed, report back */
-    if ( FILEOBJ_LINEBUFFERED(fo) ) {
-       return -3;
-    } else if ( FILEOBJ_BLOCKBUFFERED(fo) ) {
-       return -4;
-    }
-
-    /* if input stream is connect to an output stream, flush it first */
-    if ( fo->connectedTo != NULL   &&
-         fo->connectedTo->fd != -1 &&
-         (fo->connectedTo->flags & FILEOBJ_WRITE)
-       ) {
-       rc = flushFile((StgForeignPtr)fo->connectedTo);
-    }
-    if (rc < 0) return (rc == FILEOBJ_BLOCKED_WRITE ? FILEOBJ_BLOCKED_CONN_WRITE : rc);
-
-    /* RW object: flush the (output) buffer first. */
-    if ( FILEOBJ_WRITEABLE(fo) && FILEOBJ_JUST_WRITTEN(fo) && FILEOBJ_NEEDS_FLUSHING(fo) ) {
-        rc = flushBuffer(ptr);
-	if (rc < 0) return rc;
-    }
-    fo->flags = (fo->flags & ~FILEOBJ_RW_WRITE) | FILEOBJ_RW_READ;
-
-    while ( (count = 
-	       (
-#ifdef USE_WINSOCK
-	         fo->flags & FILEOBJ_WINSOCK ?
-		 recv(fo->fd, &c, 1, 0) :
-		 read(fo->fd, &c, 1))) <= 0 ) {
-#else
-		 read(fo->fd, &c, 1))) <= 0 ) {
-#endif
-	if ( count == 0 ) {
-	    ghc_errtype = ERR_EOF;
-	    ghc_errstr = "";
-	    return -1;
-	} else if ( count == -1 && errno == EAGAIN) {
-	    errno = 0;
-	    return FILEOBJ_BLOCKED_READ;
-	} else if ( count == -1 && errno != EINTR) {
-	    cvtErrno();
-	    stdErrno();
-	    return -1;
-	}
-    }
-
-    if ( isatty(fo->fd) && c == EOT ) {
-	return EOF;
-    } else {
-        return (int)c;
-    }
-}