michael@0: /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
michael@0: /* This Source Code Form is subject to the terms of the Mozilla Public
michael@0:  * License, v. 2.0. If a copy of the MPL was not distributed with this
michael@0:  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0: 
michael@0: /*
michael@0: ** File:        prlayer.c
michael@0: ** Description: Routines for handling pushable protocol modules on sockets.
michael@0: */
michael@0: 
michael@0: #include "primpl.h"
michael@0: #include "prerror.h"
michael@0: #include "prmem.h"
michael@0: #include "prlock.h"
michael@0: #include "prlog.h"
michael@0: #include "prio.h"
michael@0: 
michael@0: #include <string.h> /* for memset() */
michael@0: static PRStatus _PR_DestroyIOLayer(PRFileDesc *stack);
michael@0: 
michael@0: void PR_CALLBACK pl_FDDestructor(PRFileDesc *fd)
michael@0: {
michael@0:     PR_ASSERT(fd != NULL);
michael@0:     if (NULL != fd->lower) fd->lower->higher = fd->higher;
michael@0:     if (NULL != fd->higher) fd->higher->lower = fd->lower;
michael@0:     PR_DELETE(fd);
michael@0: }
michael@0: 
michael@0: /*
michael@0: ** Default methods that just call down to the next fd.
michael@0: */
michael@0: static PRStatus PR_CALLBACK pl_TopClose (PRFileDesc *fd)
michael@0: {
michael@0:     PRFileDesc *top, *lower;
michael@0: 	PRStatus rv;
michael@0: 
michael@0:     PR_ASSERT(fd != NULL);
michael@0:     PR_ASSERT(fd->lower != NULL);
michael@0:     PR_ASSERT(fd->secret == NULL);
michael@0:     PR_ASSERT(fd->methods->file_type == PR_DESC_LAYERED);
michael@0: 
michael@0: 	if (PR_IO_LAYER_HEAD == fd->identity) {
michael@0: 		/*
michael@0: 		 * new style stack; close all the layers, before deleting the
michael@0: 		 * stack head
michael@0: 		 */
michael@0: 		rv = fd->lower->methods->close(fd->lower);
michael@0: 		_PR_DestroyIOLayer(fd);
michael@0: 		return rv;
michael@0: 	} else if ((fd->higher) && (PR_IO_LAYER_HEAD == fd->higher->identity)) {
michael@0: 		/*
michael@0: 		 * lower layers of new style stack
michael@0: 		 */
michael@0: 		lower = fd->lower;
michael@0: 		/*
michael@0: 		 * pop and cleanup current layer
michael@0: 		 */
michael@0:     	top = PR_PopIOLayer(fd->higher, PR_TOP_IO_LAYER);
michael@0: 		top->dtor(top);
michael@0: 		/*
michael@0: 		 * then call lower layer
michael@0: 		 */
michael@0: 		return (lower->methods->close(lower));
michael@0: 	} else {
michael@0: 		/* old style stack */
michael@0:     	top = PR_PopIOLayer(fd, PR_TOP_IO_LAYER);
michael@0: 		top->dtor(top);
michael@0: 		return (fd->methods->close)(fd);
michael@0: 	}
michael@0: }
michael@0: 
michael@0: static PRInt32 PR_CALLBACK pl_DefRead (PRFileDesc *fd, void *buf, PRInt32 amount)
michael@0: {
michael@0:     PR_ASSERT(fd != NULL);
michael@0:     PR_ASSERT(fd->lower != NULL);
michael@0: 
michael@0:     return (fd->lower->methods->read)(fd->lower, buf, amount);
michael@0: }
michael@0: 
michael@0: static PRInt32 PR_CALLBACK pl_DefWrite (
michael@0:     PRFileDesc *fd, const void *buf, PRInt32 amount)
michael@0: {
michael@0:     PR_ASSERT(fd != NULL);
michael@0:     PR_ASSERT(fd->lower != NULL);
michael@0: 
michael@0:     return (fd->lower->methods->write)(fd->lower, buf, amount);
michael@0: }
michael@0: 
michael@0: static PRInt32 PR_CALLBACK pl_DefAvailable (PRFileDesc *fd)
michael@0: {
michael@0:     PR_ASSERT(fd != NULL);
michael@0:     PR_ASSERT(fd->lower != NULL);
michael@0: 
michael@0:     return (fd->lower->methods->available)(fd->lower);
michael@0: }
michael@0: 
michael@0: static PRInt64 PR_CALLBACK pl_DefAvailable64 (PRFileDesc *fd)
michael@0: {
michael@0:     PR_ASSERT(fd != NULL);
michael@0:     PR_ASSERT(fd->lower != NULL);
michael@0: 
michael@0:     return (fd->lower->methods->available64)(fd->lower);
michael@0: }
michael@0: 
michael@0: static PRStatus PR_CALLBACK pl_DefFsync (PRFileDesc *fd)
michael@0: {
michael@0:     PR_ASSERT(fd != NULL);
michael@0:     PR_ASSERT(fd->lower != NULL);
michael@0: 
michael@0:     return (fd->lower->methods->fsync)(fd->lower);
michael@0: }
michael@0: 
michael@0: static PRInt32 PR_CALLBACK pl_DefSeek (
michael@0:     PRFileDesc *fd, PRInt32 offset, PRSeekWhence how)
michael@0: {
michael@0:     PR_ASSERT(fd != NULL);
michael@0:     PR_ASSERT(fd->lower != NULL);
michael@0: 
michael@0:     return (fd->lower->methods->seek)(fd->lower, offset, how);
michael@0: }
michael@0: 
michael@0: static PRInt64 PR_CALLBACK pl_DefSeek64 (
michael@0:     PRFileDesc *fd, PRInt64 offset, PRSeekWhence how)
michael@0: {
michael@0:     PR_ASSERT(fd != NULL);
michael@0:     PR_ASSERT(fd->lower != NULL);
michael@0: 
michael@0:     return (fd->lower->methods->seek64)(fd->lower, offset, how);
michael@0: }
michael@0: 
michael@0: static PRStatus PR_CALLBACK pl_DefFileInfo (PRFileDesc *fd, PRFileInfo *info)
michael@0: {
michael@0:     PR_ASSERT(fd != NULL);
michael@0:     PR_ASSERT(fd->lower != NULL);
michael@0: 
michael@0:     return (fd->lower->methods->fileInfo)(fd->lower, info);
michael@0: }
michael@0: 
michael@0: static PRStatus PR_CALLBACK pl_DefFileInfo64 (PRFileDesc *fd, PRFileInfo64 *info)
michael@0: {
michael@0:     PR_ASSERT(fd != NULL);
michael@0:     PR_ASSERT(fd->lower != NULL);
michael@0: 
michael@0:     return (fd->lower->methods->fileInfo64)(fd->lower, info);
michael@0: }
michael@0: 
michael@0: static PRInt32 PR_CALLBACK pl_DefWritev (PRFileDesc *fd, const PRIOVec *iov,
michael@0:     PRInt32 size, PRIntervalTime timeout)
michael@0: {
michael@0:     PR_ASSERT(fd != NULL);
michael@0:     PR_ASSERT(fd->lower != NULL);
michael@0: 
michael@0:     return (fd->lower->methods->writev)(fd->lower, iov, size, timeout);
michael@0: }
michael@0: 
michael@0: static PRStatus PR_CALLBACK pl_DefConnect (
michael@0:     PRFileDesc *fd, const PRNetAddr *addr, PRIntervalTime timeout)
michael@0: {
michael@0:     PR_ASSERT(fd != NULL);
michael@0:     PR_ASSERT(fd->lower != NULL);
michael@0: 
michael@0:     return (fd->lower->methods->connect)(fd->lower, addr, timeout);
michael@0: }
michael@0: 
michael@0: static PRStatus PR_CALLBACK pl_DefConnectcontinue (
michael@0:     PRFileDesc *fd, PRInt16 out_flags)
michael@0: {
michael@0:     PR_ASSERT(fd != NULL);
michael@0:     PR_ASSERT(fd->lower != NULL);
michael@0: 
michael@0:     return (fd->lower->methods->connectcontinue)(fd->lower, out_flags);
michael@0: }
michael@0: 
michael@0: static PRFileDesc* PR_CALLBACK pl_TopAccept (
michael@0:     PRFileDesc *fd, PRNetAddr *addr, PRIntervalTime timeout)
michael@0: {
michael@0:     PRStatus rv;
michael@0:     PRFileDesc *newfd, *layer = fd;
michael@0:     PRFileDesc *newstack;
michael@0: 	PRBool newstyle_stack = PR_FALSE;
michael@0: 
michael@0:     PR_ASSERT(fd != NULL);
michael@0:     PR_ASSERT(fd->lower != NULL);
michael@0: 
michael@0: 	/* test for new style stack */
michael@0: 	while (NULL != layer->higher)
michael@0: 		layer = layer->higher;
michael@0: 	newstyle_stack = (PR_IO_LAYER_HEAD == layer->identity) ? PR_TRUE : PR_FALSE;
michael@0:     newstack = PR_NEW(PRFileDesc);
michael@0:     if (NULL == newstack)
michael@0:     {
michael@0:         PR_SetError(PR_OUT_OF_MEMORY_ERROR, 0);
michael@0:         return NULL;
michael@0:     }
michael@0:     *newstack = *fd;  /* make a copy of the accepting layer */
michael@0: 
michael@0:     newfd = (fd->lower->methods->accept)(fd->lower, addr, timeout);
michael@0:     if (NULL == newfd)
michael@0:     {
michael@0:         PR_DELETE(newstack);
michael@0:         return NULL;
michael@0:     }
michael@0: 
michael@0:     if (newstyle_stack) {
michael@0: 		newstack->lower = newfd;
michael@0: 		newfd->higher = newstack;
michael@0: 		return newstack;
michael@0: 	} else {
michael@0: 		/* this PR_PushIOLayer call cannot fail */
michael@0: 		rv = PR_PushIOLayer(newfd, PR_TOP_IO_LAYER, newstack);
michael@0: 		PR_ASSERT(PR_SUCCESS == rv);
michael@0:     	return newfd;  /* that's it */
michael@0: 	}
michael@0: }
michael@0: 
michael@0: static PRStatus PR_CALLBACK pl_DefBind (PRFileDesc *fd, const PRNetAddr *addr)
michael@0: {
michael@0:     PR_ASSERT(fd != NULL);
michael@0:     PR_ASSERT(fd->lower != NULL);
michael@0: 
michael@0:     return (fd->lower->methods->bind)(fd->lower, addr);
michael@0: }
michael@0: 
michael@0: static PRStatus PR_CALLBACK pl_DefListen (PRFileDesc *fd, PRIntn backlog)
michael@0: {
michael@0:     PR_ASSERT(fd != NULL);
michael@0:     PR_ASSERT(fd->lower != NULL);
michael@0: 
michael@0:     return (fd->lower->methods->listen)(fd->lower, backlog);
michael@0: }
michael@0: 
michael@0: static PRStatus PR_CALLBACK pl_DefShutdown (PRFileDesc *fd, PRIntn how)
michael@0: {
michael@0:     PR_ASSERT(fd != NULL);
michael@0:     PR_ASSERT(fd->lower != NULL);
michael@0: 
michael@0:     return (fd->lower->methods->shutdown)(fd->lower, how);
michael@0: }
michael@0: 
michael@0: static PRInt32 PR_CALLBACK pl_DefRecv (
michael@0:     PRFileDesc *fd, void *buf, PRInt32 amount,
michael@0:     PRIntn flags, PRIntervalTime timeout)
michael@0: {
michael@0:     PR_ASSERT(fd != NULL);
michael@0:     PR_ASSERT(fd->lower != NULL);
michael@0: 
michael@0:     return (fd->lower->methods->recv)(
michael@0:         fd->lower, buf, amount, flags, timeout);
michael@0: }
michael@0: 
michael@0: static PRInt32 PR_CALLBACK pl_DefSend (
michael@0:     PRFileDesc *fd, const void *buf,
michael@0:     PRInt32 amount, PRIntn flags, PRIntervalTime timeout)
michael@0: {
michael@0:     PR_ASSERT(fd != NULL);
michael@0:     PR_ASSERT(fd->lower != NULL);
michael@0: 
michael@0:     return (fd->lower->methods->send)(fd->lower, buf, amount, flags, timeout);
michael@0: }
michael@0: 
michael@0: static PRInt32 PR_CALLBACK pl_DefRecvfrom (
michael@0:     PRFileDesc *fd, void *buf, PRInt32 amount,
michael@0:     PRIntn flags, PRNetAddr *addr, PRIntervalTime timeout)
michael@0: {
michael@0:     PR_ASSERT(fd != NULL);
michael@0:     PR_ASSERT(fd->lower != NULL);
michael@0: 
michael@0:     return (fd->lower->methods->recvfrom)(
michael@0:         fd->lower, buf, amount, flags, addr, timeout);
michael@0: }
michael@0: 
michael@0: static PRInt32 PR_CALLBACK pl_DefSendto (
michael@0:     PRFileDesc *fd, const void *buf, PRInt32 amount, PRIntn flags,
michael@0:     const PRNetAddr *addr, PRIntervalTime timeout)
michael@0: {
michael@0:     PR_ASSERT(fd != NULL);
michael@0:     PR_ASSERT(fd->lower != NULL);
michael@0: 
michael@0:     return (fd->lower->methods->sendto)(
michael@0:         fd->lower, buf, amount, flags, addr, timeout);
michael@0: }
michael@0: 
michael@0: static PRInt16 PR_CALLBACK pl_DefPoll (
michael@0:     PRFileDesc *fd, PRInt16 in_flags, PRInt16 *out_flags)
michael@0: {
michael@0:     PR_ASSERT(fd != NULL);
michael@0:     PR_ASSERT(fd->lower != NULL);
michael@0: 
michael@0:     return (fd->lower->methods->poll)(fd->lower, in_flags, out_flags);
michael@0: }
michael@0: 
michael@0: static PRInt32 PR_CALLBACK pl_DefAcceptread (
michael@0:     PRFileDesc *sd, PRFileDesc **nd, PRNetAddr **raddr, void *buf,
michael@0:     PRInt32 amount, PRIntervalTime t)
michael@0: {
michael@0:     PRInt32 nbytes;
michael@0:     PRStatus rv;
michael@0:     PRFileDesc *newstack;
michael@0:     PRFileDesc *layer = sd;
michael@0: 	PRBool newstyle_stack = PR_FALSE;
michael@0: 
michael@0:     PR_ASSERT(sd != NULL);
michael@0:     PR_ASSERT(sd->lower != NULL);
michael@0: 
michael@0: 	/* test for new style stack */
michael@0: 	while (NULL != layer->higher)
michael@0: 		layer = layer->higher;
michael@0: 	newstyle_stack = (PR_IO_LAYER_HEAD == layer->identity) ? PR_TRUE : PR_FALSE;
michael@0:     newstack = PR_NEW(PRFileDesc);
michael@0:     if (NULL == newstack)
michael@0:     {
michael@0:         PR_SetError(PR_OUT_OF_MEMORY_ERROR, 0);
michael@0:         return -1;
michael@0:     }
michael@0:     *newstack = *sd;  /* make a copy of the accepting layer */
michael@0: 
michael@0:     nbytes = sd->lower->methods->acceptread(
michael@0:         sd->lower, nd, raddr, buf, amount, t);
michael@0:     if (-1 == nbytes)
michael@0:     {
michael@0:         PR_DELETE(newstack);
michael@0:         return nbytes;
michael@0:     }
michael@0:     if (newstyle_stack) {
michael@0: 		newstack->lower = *nd;
michael@0: 		(*nd)->higher = newstack;
michael@0: 		*nd = newstack;
michael@0: 		return nbytes;
michael@0: 	} else {
michael@0: 		/* this PR_PushIOLayer call cannot fail */
michael@0: 		rv = PR_PushIOLayer(*nd, PR_TOP_IO_LAYER, newstack);
michael@0: 		PR_ASSERT(PR_SUCCESS == rv);
michael@0: 		return nbytes;
michael@0: 	}
michael@0: }
michael@0: 
michael@0: static PRInt32 PR_CALLBACK pl_DefTransmitfile (
michael@0:     PRFileDesc *sd, PRFileDesc *fd, const void *headers, PRInt32 hlen,
michael@0:     PRTransmitFileFlags flags, PRIntervalTime t)
michael@0: {
michael@0:     PR_ASSERT(sd != NULL);
michael@0:     PR_ASSERT(sd->lower != NULL);
michael@0: 
michael@0:     return sd->lower->methods->transmitfile(
michael@0:         sd->lower, fd, headers, hlen, flags, t);
michael@0: }
michael@0: 
michael@0: static PRStatus PR_CALLBACK pl_DefGetsockname (PRFileDesc *fd, PRNetAddr *addr)
michael@0: {
michael@0:     PR_ASSERT(fd != NULL);
michael@0:     PR_ASSERT(fd->lower != NULL);
michael@0: 
michael@0:     return (fd->lower->methods->getsockname)(fd->lower, addr);
michael@0: }
michael@0: 
michael@0: static PRStatus PR_CALLBACK pl_DefGetpeername (PRFileDesc *fd, PRNetAddr *addr)
michael@0: {
michael@0:     PR_ASSERT(fd != NULL);
michael@0:     PR_ASSERT(fd->lower != NULL);
michael@0: 
michael@0:     return (fd->lower->methods->getpeername)(fd->lower, addr);
michael@0: }
michael@0: 
michael@0: static PRStatus PR_CALLBACK pl_DefGetsocketoption (
michael@0:     PRFileDesc *fd, PRSocketOptionData *data)
michael@0: {
michael@0:     PR_ASSERT(fd != NULL);
michael@0:     PR_ASSERT(fd->lower != NULL);
michael@0: 
michael@0:     return (fd->lower->methods->getsocketoption)(fd->lower, data);
michael@0: }
michael@0: 
michael@0: static PRStatus PR_CALLBACK pl_DefSetsocketoption (
michael@0:     PRFileDesc *fd, const PRSocketOptionData *data)
michael@0: {
michael@0:     PR_ASSERT(fd != NULL);
michael@0:     PR_ASSERT(fd->lower != NULL);
michael@0: 
michael@0:     return (fd->lower->methods->setsocketoption)(fd->lower, data);
michael@0: }
michael@0: 
michael@0: static PRInt32 PR_CALLBACK pl_DefSendfile (
michael@0: 	PRFileDesc *sd, PRSendFileData *sfd,
michael@0: 	PRTransmitFileFlags flags, PRIntervalTime timeout)
michael@0: {
michael@0:     PR_ASSERT(sd != NULL);
michael@0:     PR_ASSERT(sd->lower != NULL);
michael@0: 
michael@0:     return sd->lower->methods->sendfile(
michael@0:         sd->lower, sfd, flags, timeout);
michael@0: }
michael@0: 
michael@0: /* Methods for the top of the stack.  Just call down to the next fd. */
michael@0: static PRIOMethods pl_methods = {
michael@0:     PR_DESC_LAYERED,
michael@0:     pl_TopClose,
michael@0:     pl_DefRead,
michael@0:     pl_DefWrite,
michael@0:     pl_DefAvailable,
michael@0:     pl_DefAvailable64,
michael@0:     pl_DefFsync,
michael@0:     pl_DefSeek,
michael@0:     pl_DefSeek64,
michael@0:     pl_DefFileInfo,
michael@0:     pl_DefFileInfo64,
michael@0:     pl_DefWritev,
michael@0:     pl_DefConnect,
michael@0:     pl_TopAccept,
michael@0:     pl_DefBind,
michael@0:     pl_DefListen,
michael@0:     pl_DefShutdown,
michael@0:     pl_DefRecv,
michael@0:     pl_DefSend,
michael@0:     pl_DefRecvfrom,
michael@0:     pl_DefSendto,
michael@0:     pl_DefPoll,
michael@0:     pl_DefAcceptread,
michael@0:     pl_DefTransmitfile,
michael@0:     pl_DefGetsockname,
michael@0:     pl_DefGetpeername,
michael@0:     (PRReservedFN)_PR_InvalidInt,
michael@0:     (PRReservedFN)_PR_InvalidInt,
michael@0:     pl_DefGetsocketoption,
michael@0:     pl_DefSetsocketoption,
michael@0:     pl_DefSendfile,
michael@0:     pl_DefConnectcontinue,
michael@0:     (PRReservedFN)_PR_InvalidInt,
michael@0:     (PRReservedFN)_PR_InvalidInt,
michael@0:     (PRReservedFN)_PR_InvalidInt,
michael@0:     (PRReservedFN)_PR_InvalidInt
michael@0: };
michael@0: 
michael@0: PR_IMPLEMENT(const PRIOMethods*) PR_GetDefaultIOMethods(void)
michael@0: {
michael@0:     return &pl_methods;
michael@0: }  /* PR_GetDefaultIOMethods */
michael@0: 
michael@0: PR_IMPLEMENT(PRFileDesc*) PR_CreateIOLayerStub(
michael@0:     PRDescIdentity ident, const PRIOMethods *methods)
michael@0: {
michael@0:     PRFileDesc *fd = NULL;
michael@0:     PR_ASSERT((PR_NSPR_IO_LAYER != ident) && (PR_TOP_IO_LAYER != ident));
michael@0:     if ((PR_NSPR_IO_LAYER == ident) || (PR_TOP_IO_LAYER == ident))
michael@0:         PR_SetError(PR_INVALID_ARGUMENT_ERROR, 0);
michael@0:     else
michael@0:     {
michael@0:         fd = PR_NEWZAP(PRFileDesc);
michael@0:         if (NULL == fd)
michael@0:             PR_SetError(PR_OUT_OF_MEMORY_ERROR, 0);
michael@0:         else
michael@0:         {
michael@0:             fd->methods = methods;
michael@0:             fd->dtor = pl_FDDestructor;
michael@0:             fd->identity = ident;
michael@0:         }
michael@0:     }
michael@0:     return fd;
michael@0: }  /* PR_CreateIOLayerStub */
michael@0: 
michael@0: /*
michael@0:  * PR_CreateIOLayer
michael@0:  *		Create a new style stack, where the stack top is a dummy header.
michael@0:  *		Unlike the old style stacks, the contents of the stack head
michael@0:  *		are not modified when a layer is pushed onto or popped from a new
michael@0:  *		style stack.
michael@0:  */
michael@0: 
michael@0: PR_IMPLEMENT(PRFileDesc*) PR_CreateIOLayer(PRFileDesc *top)
michael@0: {
michael@0:     PRFileDesc *fd = NULL;
michael@0: 
michael@0: 	fd = PR_NEWZAP(PRFileDesc);
michael@0: 	if (NULL == fd)
michael@0: 		PR_SetError(PR_OUT_OF_MEMORY_ERROR, 0);
michael@0: 	else
michael@0: 	{
michael@0: 		fd->methods = &pl_methods;
michael@0: 		fd->dtor = pl_FDDestructor;
michael@0: 		fd->identity = PR_IO_LAYER_HEAD;
michael@0: 		fd->higher = NULL;
michael@0: 		fd->lower = top;
michael@0: 		top->higher = fd;
michael@0: 		top->lower = NULL;
michael@0: 	}
michael@0:     return fd;
michael@0: }  /* PR_CreateIOLayer */
michael@0: 
michael@0: /*
michael@0:  * _PR_DestroyIOLayer
michael@0:  *		Delete the stack head of a new style stack.
michael@0:  */
michael@0: 
michael@0: static PRStatus _PR_DestroyIOLayer(PRFileDesc *stack)
michael@0: {
michael@0:     if (NULL == stack)
michael@0:         return PR_FAILURE;
michael@0:     else {
michael@0:         PR_DELETE(stack);
michael@0:     	return PR_SUCCESS;
michael@0:     }
michael@0: }  /* _PR_DestroyIOLayer */
michael@0: 
michael@0: PR_IMPLEMENT(PRStatus) PR_PushIOLayer(
michael@0:     PRFileDesc *stack, PRDescIdentity id, PRFileDesc *fd)
michael@0: {
michael@0:     PRFileDesc *insert = PR_GetIdentitiesLayer(stack, id);
michael@0: 
michael@0:     PR_ASSERT(fd != NULL);
michael@0:     PR_ASSERT(stack != NULL);
michael@0:     PR_ASSERT(insert != NULL);
michael@0:     PR_ASSERT(PR_IO_LAYER_HEAD != id);
michael@0:     if ((NULL == stack) || (NULL == fd) || (NULL == insert))
michael@0:     {
michael@0:         PR_SetError(PR_INVALID_ARGUMENT_ERROR, 0);
michael@0:         return PR_FAILURE;
michael@0:     }
michael@0: 
michael@0:     if (stack == insert)
michael@0:     {
michael@0: 		/* going on top of the stack */
michael@0: 		/* old-style stack */	
michael@0: 		PRFileDesc copy = *stack;
michael@0: 		*stack = *fd;
michael@0: 		*fd = copy;
michael@0: 		fd->higher = stack;
michael@0: 		if (fd->lower)
michael@0: 		{
michael@0: 			PR_ASSERT(fd->lower->higher == stack);
michael@0: 			fd->lower->higher = fd;
michael@0: 		}
michael@0: 		stack->lower = fd;
michael@0: 		stack->higher = NULL;
michael@0: 	} else {
michael@0:         /*
michael@0: 		 * going somewhere in the middle of the stack for both old and new
michael@0: 		 * style stacks, or going on top of stack for new style stack
michael@0: 		 */
michael@0:         fd->lower = insert;
michael@0:         fd->higher = insert->higher;
michael@0: 
michael@0:         insert->higher->lower = fd;
michael@0:         insert->higher = fd;
michael@0:     }
michael@0: 
michael@0:     return PR_SUCCESS;
michael@0: }
michael@0: 
michael@0: PR_IMPLEMENT(PRFileDesc*) PR_PopIOLayer(PRFileDesc *stack, PRDescIdentity id)
michael@0: {
michael@0:     PRFileDesc *extract = PR_GetIdentitiesLayer(stack, id);
michael@0: 
michael@0:     PR_ASSERT(0 != id);
michael@0:     PR_ASSERT(NULL != stack);
michael@0:     PR_ASSERT(NULL != extract);
michael@0:     if ((NULL == stack) || (0 == id) || (NULL == extract))
michael@0:     {
michael@0:         PR_SetError(PR_INVALID_ARGUMENT_ERROR, 0);
michael@0:         return NULL;
michael@0:     }
michael@0: 
michael@0:     if (extract == stack) {
michael@0:         /* popping top layer of the stack */
michael@0: 		/* old style stack */
michael@0:         PRFileDesc copy = *stack;
michael@0:         extract = stack->lower;
michael@0:         *stack = *extract;
michael@0:         *extract = copy;
michael@0:         stack->higher = NULL;
michael@0:         if (stack->lower) {
michael@0:             PR_ASSERT(stack->lower->higher == extract);
michael@0:             stack->lower->higher = stack;
michael@0:         }
michael@0: 	} else if ((PR_IO_LAYER_HEAD == stack->identity) &&
michael@0: 					(extract == stack->lower) && (extract->lower == NULL)) {
michael@0: 			/*
michael@0: 			 * new style stack
michael@0: 			 * popping the only layer in the stack; delete the stack too
michael@0: 			 */
michael@0: 			stack->lower = NULL;
michael@0: 			_PR_DestroyIOLayer(stack);
michael@0: 	} else {
michael@0: 		/* for both kinds of stacks */
michael@0:         extract->lower->higher = extract->higher;
michael@0:         extract->higher->lower = extract->lower;
michael@0:     }
michael@0:     extract->higher = extract->lower = NULL;
michael@0:     return extract;
michael@0: }  /* PR_PopIOLayer */
michael@0: 
michael@0: #define ID_CACHE_INCREMENT 16
michael@0: typedef struct _PRIdentity_cache
michael@0: {
michael@0:     PRLock *ml;
michael@0:     char **name;
michael@0:     PRIntn length;
michael@0:     PRDescIdentity ident;
michael@0: } _PRIdentity_cache;
michael@0: 
michael@0: static _PRIdentity_cache identity_cache;
michael@0: 
michael@0: PR_IMPLEMENT(PRDescIdentity) PR_GetUniqueIdentity(const char *layer_name)
michael@0: {
michael@0:     PRDescIdentity identity, length;
michael@0:     char **names = NULL, *name = NULL, **old = NULL;
michael@0: 
michael@0:     if (!_pr_initialized) _PR_ImplicitInitialization();
michael@0: 
michael@0:     PR_ASSERT((PRDescIdentity)0x7fff > identity_cache.ident);
michael@0: 
michael@0:     if (NULL != layer_name)
michael@0:     {
michael@0:         name = (char*)PR_Malloc(strlen(layer_name) + 1);
michael@0:         if (NULL == name)
michael@0:         {
michael@0:             PR_SetError(PR_OUT_OF_MEMORY_ERROR, 0);
michael@0:             return PR_INVALID_IO_LAYER;
michael@0:         }
michael@0:         strcpy(name, layer_name);
michael@0:     }
michael@0: 
michael@0:     /* this initial code runs unsafe */
michael@0: retry:
michael@0:     PR_ASSERT(NULL == names);
michael@0:     /*
michael@0:      * In the initial round, both identity_cache.ident and
michael@0:      * identity_cache.length are 0, so (identity_cache.ident + 1) is greater
michael@0:      * than length.  In later rounds, identity_cache.ident is always less
michael@0:      * than length, so (identity_cache.ident + 1) can be equal to but cannot
michael@0:      * be greater than length.
michael@0:      */
michael@0:     length = identity_cache.length;
michael@0:     if ((identity_cache.ident + 1) >= length)
michael@0:     {
michael@0:         length += ID_CACHE_INCREMENT;
michael@0:         names = (char**)PR_CALLOC(length * sizeof(char*));
michael@0:         if (NULL == names)
michael@0:         {
michael@0:             if (NULL != name) PR_DELETE(name);
michael@0:             PR_SetError(PR_OUT_OF_MEMORY_ERROR, 0);
michael@0:             return PR_INVALID_IO_LAYER;
michael@0:         }
michael@0:     }
michael@0: 
michael@0:     /* now we get serious about thread safety */
michael@0:     PR_Lock(identity_cache.ml);
michael@0:     PR_ASSERT(identity_cache.length == 0 ||
michael@0:               identity_cache.ident < identity_cache.length);
michael@0:     identity = identity_cache.ident + 1;
michael@0:     if (identity >= identity_cache.length)  /* there's no room */
michael@0:     {
michael@0:         /* we have to do something - hopefully it's already done */
michael@0:         if ((NULL != names) && (identity < length))
michael@0:         {
michael@0:             /* what we did is still okay */
michael@0:             memcpy(
michael@0:                 names, identity_cache.name,
michael@0:                 identity_cache.length * sizeof(char*));
michael@0:             old = identity_cache.name;
michael@0:             identity_cache.name = names;
michael@0:             identity_cache.length = length;
michael@0:             names = NULL;
michael@0:         }
michael@0:         else
michael@0:         {
michael@0:             PR_Unlock(identity_cache.ml);
michael@0:             if (NULL != names) PR_DELETE(names);
michael@0:             goto retry;
michael@0:         }
michael@0:     }
michael@0:     if (NULL != name) /* there's a name to be stored */
michael@0:     {
michael@0:         identity_cache.name[identity] = name;
michael@0:     }
michael@0:     identity_cache.ident = identity;
michael@0:     PR_ASSERT(identity_cache.ident < identity_cache.length);
michael@0:     PR_Unlock(identity_cache.ml);
michael@0: 
michael@0:     if (NULL != old) PR_DELETE(old);
michael@0:     if (NULL != names) PR_DELETE(names);
michael@0: 
michael@0:     return identity;
michael@0: }  /* PR_GetUniqueIdentity */
michael@0: 
michael@0: PR_IMPLEMENT(const char*) PR_GetNameForIdentity(PRDescIdentity ident)
michael@0: {
michael@0:     if (!_pr_initialized) _PR_ImplicitInitialization();
michael@0: 
michael@0:     if (PR_TOP_IO_LAYER == ident) return NULL;
michael@0: 
michael@0:     PR_ASSERT(ident <= identity_cache.ident);
michael@0:     return (ident > identity_cache.ident) ? NULL : identity_cache.name[ident];
michael@0: }  /* PR_GetNameForIdentity */
michael@0: 
michael@0: PR_IMPLEMENT(PRDescIdentity) PR_GetLayersIdentity(PRFileDesc* fd)
michael@0: {
michael@0:     PR_ASSERT(NULL != fd);
michael@0:     if (PR_IO_LAYER_HEAD == fd->identity) {
michael@0:     	PR_ASSERT(NULL != fd->lower);
michael@0:     	return fd->lower->identity;
michael@0: 	} else
michael@0:     	return fd->identity;
michael@0: }  /* PR_GetLayersIdentity */
michael@0: 
michael@0: PR_IMPLEMENT(PRFileDesc*) PR_GetIdentitiesLayer(PRFileDesc* fd, PRDescIdentity id)
michael@0: {
michael@0:     PRFileDesc *layer = fd;
michael@0: 
michael@0:     if (PR_TOP_IO_LAYER == id) {
michael@0:     	if (PR_IO_LAYER_HEAD == fd->identity)
michael@0: 			return fd->lower;
michael@0: 		else 
michael@0: 			return fd;
michael@0: 	}
michael@0: 
michael@0:     for (layer = fd; layer != NULL; layer = layer->lower)
michael@0:     {
michael@0:         if (id == layer->identity) return layer;
michael@0:     }
michael@0:     for (layer = fd; layer != NULL; layer = layer->higher)
michael@0:     {
michael@0:         if (id == layer->identity) return layer;
michael@0:     }
michael@0:     return NULL;
michael@0: }  /* PR_GetIdentitiesLayer */
michael@0: 
michael@0: void _PR_InitLayerCache(void)
michael@0: {
michael@0:     memset(&identity_cache, 0, sizeof(identity_cache));
michael@0:     identity_cache.ml = PR_NewLock();
michael@0:     PR_ASSERT(NULL != identity_cache.ml);
michael@0: }  /* _PR_InitLayerCache */
michael@0: 
michael@0: void _PR_CleanupLayerCache(void)
michael@0: {
michael@0:     if (identity_cache.ml)
michael@0:     {
michael@0:         PR_DestroyLock(identity_cache.ml);
michael@0:         identity_cache.ml = NULL;
michael@0:     }
michael@0: 
michael@0:     if (identity_cache.name)
michael@0:     {
michael@0:         PRDescIdentity ident;
michael@0: 
michael@0:         for (ident = 0; ident <= identity_cache.ident; ident++)
michael@0:             PR_DELETE(identity_cache.name[ident]);
michael@0: 
michael@0:         PR_DELETE(identity_cache.name);
michael@0:     }
michael@0: }  /* _PR_CleanupLayerCache */
michael@0: 
michael@0: /* prlayer.c */