used in the new multi interface, not yet actually part of libcurl but

added to CVS to make them available to others

2 files changed, 444 insertions, 0 deletions

diff --git a/lib/multi.c b/lib/multi.c
new file mode 100644
index 000000000..7d396c61d
--- /dev/null
+++ b/lib/multi.c
@@ -0,0 +1,244 @@
+/*****************************************************************************
+ *                                  _   _ ____  _     
+ *  Project                     ___| | | |  _ \| |    
+ *                             / __| | | | |_) | |    
+ *                            | (__| |_| |  _ <| |___ 
+ *                             \___|\___/|_| \_\_____|
+ *
+ * Copyright (C) 2001, Daniel Stenberg, <daniel@haxx.se>, et al.
+ *
+ * In order to be useful for every potential user, curl and libcurl are
+ * dual-licensed under the MPL and the MIT/X-derivate licenses.
+ *
+ * You may opt to use, copy, modify, merge, publish, distribute and/or sell
+ * copies of the Software, and permit persons to whom the Software is
+ * furnished to do so, under the terms of the MPL or the MIT/X-derivate
+ * licenses. You may pick one of these licenses.
+ *
+ * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
+ * KIND, either express or implied.
+ *
+ * $Id$
+ *****************************************************************************/
+
+#include "setup.h"
+
+#include "multi.h" /* will become <curl/multi.h> soon */
+
+typedef enum {
+  CURLM_STATE_INIT,
+  CURLM_STATE_CONNECT,
+  CURLM_STATE_DO,
+  CURLM_STATE_PERFORM,
+  CURLM_STATE_DONE,
+  CURLM_STATE_COMPLETED,
+
+  CURLM_STATE_LAST /* not a true state, never use this */
+} CURLMstate;
+
+struct Curl_one_easy {
+  /* first, two fields for the linked list of these */
+  struct Curl_one_easy *next;
+  struct Curl_one_easy *prev;
+  
+  CURL *easy_handle; /* this is the easy handle for this unit */
+  CURLMstate state; /* the handle's state */
+};
+
+
+#define CURL_MULTI_HANDLE 0x000bab1e
+
+#define GOOD_MULTI_HANDLE(x) ((x) && ((x)->type == CURL_MULTI_HANDLE))
+#define GOOD_EASY_HANDLE(x) (x)
+
+/* This is the struct known as CURLM on the outside */
+struct Curl_multi {
+  /* First a simple identifier to easier detect if a user mix up
+     this multi handle with an easy handle. Set this to CURL_MULTI_HANDLE. */
+  long type;
+
+  /* We have a linked list with easy handles */
+  struct Curl_one_easy first; 
+  /* This is the amount of entries in the linked list above. */
+  int num_easy;
+};
+
+
+CURLM *curl_multi_init(void)
+{
+  struct Curl_multi *multi;
+
+  multi = (void *)malloc(sizeof(struct Curl_multi));
+
+  if(multi) {
+    memset(multi, 0, sizeof(struct Curl_multi));
+    multi->type = CURL_MULTI_HANDLE;
+  }
+  
+  return (CURLM *) multi;
+}
+
+CURLMcode curl_multi_add_handle(CURLM *multi_handle,
+                                CURL *easy_handle)
+{
+  struct Curl_multi *multi=(struct Curl_multi *)multi_handle;
+  struct Curl_one_easy *easy;
+
+  /* First, make some basic checks that the CURLM handle is a good handle */
+  if(!GOOD_MULTI_HANDLE(multi))
+    return CURLM_BAD_HANDLE;
+  
+  /* Verify that we got a somewhat good easy handle too */
+  if(!GOOD_EASY_HANDLE(easy_handle))
+    return CURLM_BAD_EASY_HANDLE;
+
+  /* Now, time to add an easy handle to the multi stack */
+  easy = (struct Curl_one_easy *)malloc(sizeof(struct Curl_one_easy));
+  if(!easy)
+    return CURLM_OUT_OF_MEMORY;
+  
+  /* clean it all first (just to be sure) */
+  memset(easy, 0, sizeof(struct Curl_one_easy));
+
+  /* set the easy handle */
+  easy->easy_handle = easy_handle;
+  easy->state = CURLM_STATE_INIT;
+  
+  /* We add this new entry first in the list. We make our 'next' point to the
+     previous next and our 'prev' point back to the 'first' struct */
+  easy->next = multi->first.next;
+  easy->prev = &multi->first; 
+
+  /* make 'easy' the first node in the chain */
+  multi->first.next = easy;
+
+  /* if there was a next node, make sure its 'prev' pointer links back to
+     the new node */
+  if(easy->next)
+    easy->next->prev = easy;
+
+  /* increase the node-counter */
+  multi->num_easy++;
+
+  return CURLM_OK;
+}
+
+CURLMcode curl_multi_remove_handle(CURLM *multi_handle,
+                                   CURL *curl_handle)
+{
+  struct Curl_multi *multi=(struct Curl_multi *)multi_handle;
+  struct Curl_one_easy *easy;
+
+  /* First, make some basic checks that the CURLM handle is a good handle */
+  if(!GOOD_MULTI_HANDLE(multi))
+    return CURLM_BAD_HANDLE;
+  
+  /* Verify that we got a somewhat good easy handle too */
+  if(!GOOD_EASY_HANDLE(curl_handle))
+    return CURLM_BAD_EASY_HANDLE;
+
+  /* scan through the list and remove the 'curl_handle' */
+  easy = multi->first.next;
+  while(easy) {
+    if(easy->easy_handle == curl_handle)
+      break;
+    easy=easy->next;
+  }
+  if(easy) {
+    /* If the 'state' is not INIT or COMPLETED, we might need to do something
+       nice to put the easy_handle in a good known state when this returns. */
+
+    /* make the previous node point to our next */
+    if(easy->prev)
+      easy->prev->next = easy->next;
+    /* make our next point to our previous node */
+    if(easy->next)
+      easy->next->prev = easy->prev;
+    
+    /* NOTE NOTE NOTE
+       We do not touch the easy handle here! */
+    free(easy);
+
+    return CURLM_OK;
+  }
+  else
+    return CURLM_BAD_EASY_HANDLE; /* twasn't found */
+}
+
+CURLMcode curl_multi_fdset(CURLM *multi_handle,
+                           fd_set *read_fd_set, fd_set *write_fd_set,
+                           fd_set *exc_fd_set, int *max_fd)
+{
+  /* Scan through all the easy handles to get the file descriptors set.
+     Some easy handles may not have connected to the remote host yet,
+     and then we must make sure that is done. */
+  struct Curl_multi *multi=(struct Curl_multi *)multi_handle;
+  struct Curl_one_easy *easy;
+
+  if(!GOOD_MULTI_HANDLE(multi))
+    return CURLM_BAD_HANDLE;
+
+  easy=multi->first.next;
+  while(easy) {
+    switch(easy->state) {
+    case CURLM_STATE_INIT:
+    case CURLM_STATE_CONNECT:
+    case CURLM_STATE_DO:
+    case CURLM_STATE_DONE:
+      /* we want curl_multi_perform() to get called, but we don't have any
+         file descriptors to set */
+      break;
+    case CURLM_STATE_PERFORM:
+      /* This should have a set of file descriptors for us to set.  */
+      /* after the transfer is done, go DONE */
+      break;
+    }
+
+  }
+
+  return CURLM_OK;
+}
+
+CURLMcode curl_multi_perform(CURLM *multi_handle, int *running_handles)
+{
+  struct Curl_multi *multi=(struct Curl_multi *)multi_handle;
+  struct Curl_one_easy *easy;
+
+  if(!GOOD_MULTI_HANDLE(multi))
+    return CURLM_BAD_HANDLE;
+
+  easy=multi->first.next;
+  while(easy) {
+    switch(easy->state) {
+    case CURLM_STATE_INIT:
+      /* after init, go CONNECT */
+      break;
+    case CURLM_STATE_CONNECT:
+      /* after connect, go DO */
+      break;
+    case CURLM_STATE_DO:
+      /* after do, go PERFORM */
+      break;
+    case CURLM_STATE_PERFORM:
+      /* read/write data if it is ready to do so */
+      /* after the transfer is done, go DONE */
+      break;
+    case CURLM_STATE_DONE:
+      /* after we have DONE what we're supposed to do, go COMPLETED */
+      break;
+    case CURLM_STATE_COMPLETED:
+      /* this is a completed transfer */
+      break;
+    }
+
+  }
+
+}
+
+CURLMcode curl_multi_cleanup(CURLM *multi_handle);
+
+int curl_multi_info_open(CURLM *multi_handle, CURLMinfo *info_handle);
+
+CURLMsg *curl_multi_info_read(CURLMinfo *info_handle);
+
+void curl_multi_info_close(CURLMinfo *info_handle);
diff --git a/lib/multi.h b/lib/multi.h
new file mode 100644
index 000000000..e930e52a5
--- /dev/null
+++ b/lib/multi.h
@@ -0,0 +1,200 @@
+#ifndef __CURL_MULTI_H
+#define __CURL_MULTI_H
+/*****************************************************************************
+ *                                  _   _ ____  _     
+ *  Project                     ___| | | |  _ \| |    
+ *                             / __| | | | |_) | |    
+ *                            | (__| |_| |  _ <| |___ 
+ *                             \___|\___/|_| \_\_____|
+ *
+ * Copyright (C) 2001, Daniel Stenberg, <daniel@haxx.se>, et al.
+ *
+ * In order to be useful for every potential user, curl and libcurl are
+ * dual-licensed under the MPL and the MIT/X-derivate licenses.
+ *
+ * You may opt to use, copy, modify, merge, publish, distribute and/or sell
+ * copies of the Software, and permit persons to whom the Software is
+ * furnished to do so, under the terms of the MPL or the MIT/X-derivate
+ * licenses. You may pick one of these licenses.
+ *
+ * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
+ * KIND, either express or implied.
+ *
+ * $Id$
+ *****************************************************************************/
+/*
+  This is meant to be the "external" header file. Don't give away any
+  internals here!
+
+  This document presents a mixture of ideas from at least:
+  - Daniel Stenberg
+  - Steve Dekorte
+  - Sterling Hughes
+  - Ben Greear
+
+  -------------------------------------------
+  GOALS
+
+  o Enable a "pull" interface. The application that uses libcurl decides where
+    and when to ask libcurl to get/send data.
+
+  o Enable multiple simultaneous transfers without using threads or making it
+    very complicated for the application.
+
+  o Enable the application to select() on its own file descriptors and curl's
+    file descriptors simultaneous easily.
+  
+  Example source using this interface: http://curl.haxx.se/dev/multi-app.c
+
+*/
+#ifdef HAVE_SYS_SOCKET_H
+#include <sys/socket.h>
+#endif
+#include <curl/types.h>
+
+typedef void CURLM;
+
+typedef enum {
+  CURLM_OK,
+  CURLM_BAD_HANDLE,      /* the passed-in handle is not a valid CURLM handle */
+  CURLM_BAD_EASY_HANDLE, /* an easy handle was not good/valid */
+  CURLM_OUT_OF_MEMORY,   /* if you ever get this, you're in deep sh*t */
+  CURLM_LAST
+} CURLMcode;
+
+struct CURLMsg {
+  CURL *easy_handle;
+  void *whatever;
+};
+typedef struct CURLMsg CURLMsg;
+
+typedef void * CURLMinfo;
+
+/*
+ * Desc:    inititalize multi-style curl usage
+ * Name:    curl_multi_init()
+ * Returns: a new CURLM handle to use in all 'curl_multi' functions.
+ */
+CURLM *curl_multi_init(void);
+
+/*
+ * Desc:    add a standard curl handle to the multi stack
+ * Name:    curl_multi_add_handle()
+ * Returns: CURLMcode type, general error code.
+ */
+CURLMcode curl_multi_add_handle(CURLM *multi_handle,
+                                CURL *curl_handle);
+
+ /*
+  * Desc:    removes a curl handle from the multi stack again
+  * Name:    curl_multi_remove_handle()
+  * Returns: CURLMcode type, general error code.
+  */
+CURLMcode curl_multi_remove_handle(CURLM *multi_handle,
+                                   CURL *curl_handle);
+
+ /*
+  * Desc:    Ask curl for its fd_set sets. The app can use these to select() or
+  *          poll() on. We want curl_multi_perform() called as soon as one of
+  *          them are ready.
+  * Name:    curl_multi_fdset()
+  * Returns: CURLMcode type, general error code.
+  */
+CURLMcode curl_multi_fdset(CURLM *multi_handle,
+                           fd_set *read_fd_set, fd_set *write_fd_set,
+                           fd_set *exc_fd_set, int *max_fd);
+
+ /*
+  * Desc:    When the app thinks there's data available for curl it calls this
+  *          function to read/write whatever there is right now. This returns
+  *          as soon as the reads and writes are done. This function does not
+  *          require that there actually is data available for reading or that
+  *          data can be written, it can be called just in case. It returns
+  *          the number of handles that still transfer data in the second
+  *          argument's integer-pointer.
+  * Name:    curl_multi_fdset()
+  * Returns: CURLMcode type, general error code. *NOTE* that this only returns
+  *          errors etc regardin the whole multi stack. There might still have
+  *          occurred problems on invidual transfers even when this returns OK.
+  */
+
+CURLMcode curl_multi_perform(CURLM *multi_handle, int *running_handles);
+
+ /*
+  * Desc:    Cleans up and removes a whole multi stack.
+  * Name:    curl_multi_cleanup()
+  * Returns: CURLMcode type, general error code.
+  */
+CURLMcode curl_multi_cleanup(CURLM *multi_handle);
+
+/* ---------------------------------------------------------------------- */
+/*
+ * I suggest an fopen style system to get information from the multi layer.
+ * I've named these functions "curl_multi_info*" something to make it apparent
+ * that they belong together.
+ *
+ * I expect that the curl_multi_info_open will be used fairly often after
+ * calls to curl_multi_perform(), but there's nothing in this design that
+ * forces the application to invoke it at that particular time. In fact, many
+ * applications will do good without using it at all.  */
+
+/*
+ * Desc:    Ask the multi handle if there's any messages/informationals from
+ *          the individual transfers. We pass a pointer to a 'CURLMinfo' that
+ *          can be used as input in a subsequent call to curl_multi_info_read.
+ *
+ *          Messages include informationals such as error code from the
+ *          transfer or just the fact that a transfer is completed. More
+ *          details on these should be written down as well.
+ *
+ * Name:    curl_multi_info_open()
+ * Returns: The number of transfers that have information stored that can be
+ *          read. If zero is returned, there's no need to call
+ *          curl_multi_info_close() on the returned handle, but there's no
+ *          harm in doing so.
+ */
+int curl_multi_info_open(CURLM *multi_handle, CURLMinfo *info_handle);
+
+/*
+ * Desc:    Returns a pointer to a filled-in struct with information.
+ *
+ *          Repeated calls to this function will return a new struct each
+ *          time, until a special "end of msgs" struct is returned as a signal
+ *          that there is no more to get at this point.
+ *
+ *          curl_multi_info_close() should be called when the last info has
+ *          been read. In fact, it must be called if curl_multi_info_open()
+ *          was called.
+ *
+ *          The data the returned pointer points to will not survive calling
+ *          curl_multi_cleanup().
+ *
+ *          The 'CURLMsg' struct is meant to be very simple and only contain
+ *          very basic informations. If more involved information is wanted,
+ *          we will provide the particular "transfer handle" in that struct
+ *          and that should/could/would be used in subsequent
+ *          curl_easy_getinfo() calls (or similar). The point being that we
+ *          must never expose complex structs to applications, as then we'll
+ *          undoubtably get backwards compatibility problems in the future.
+ *
+ * Name:    curl_multi_info_read()
+ *
+ * Returns: A pointer to a struct, or NULL if it failed or ran out of structs.
+ *          Note that if you continue reading until you get a NULL, you did
+ *          read at least one too many times!
+ */
+CURLMsg *curl_multi_info_read(CURLMinfo *info_handle);
+
+/*
+ * Desc:    Terminates an info reading "session".
+ *
+ * Name:    curl_multi_info_close()
+ *
+ * Returns: When we've read all the info we want from the info_handle, we
+ *          signal this to the multi system by calling this function.
+ *          After this call, the info_handle can no longer be used.
+ *
+ */
+void curl_multi_info_close(CURLMinfo *info_handle);
+
+#endif