Refactoring and plugin support

1 files changed, 356 insertions, 2 deletions

diff --git a/src/uscxml/URL.cpp b/src/uscxml/URL.cpp
index 722352d..991c875 100644
--- a/src/uscxml/URL.cpp
+++ b/src/uscxml/URL.cpp
@@ -1,7 +1,17 @@
-#include "URL.h"
 #include <glog/logging.h>
 #include <algorithm>
 
+#include <stdio.h>
+#include <string.h>
+#ifndef WIN32
+#include <sys/time.h>
+#endif
+#include <stdlib.h>
+#include <errno.h>
+
+#include "uscxml/Common.h"
+#include "URL.h"
+
 namespace uscxml {
 		
 std::ostream & operator<<(std::ostream & stream, const URL& url) {
@@ -37,5 +47,349 @@ std::ostream & operator<<(std::ostream & stream, const URL& url) {
 	return stream;
 }
 	
-	
+/* we use a global one for convenience */ 
+CURLM *multi_handle;
+
+/* curl calls this routine to get more data */ 
+static size_t write_callback(char *buffer,
+                             size_t size,
+                             size_t nitems,
+                             void *userp)
+{
+  char *newbuff;
+  size_t rembuff;
+ 
+  URL_FILE *url = (URL_FILE *)userp;
+  size *= nitems;
+ 
+  rembuff=url->buffer_len - url->buffer_pos; /* remaining space in buffer */ 
+ 
+  if(size > rembuff) {
+    /* not enough space in buffer */ 
+    newbuff=(char*)realloc(url->buffer,url->buffer_len + (size - rembuff));
+    if(newbuff==NULL) {
+      fprintf(stderr,"callback buffer grow failed\n");
+      size=rembuff;
+    }
+    else {
+      /* realloc suceeded increase buffer size*/ 
+      url->buffer_len+=size - rembuff;
+      url->buffer=newbuff;
+    }
+  }
+ 
+  memcpy(&url->buffer[url->buffer_pos], buffer, size);
+  url->buffer_pos += size;
+ 
+  return size;
+}
+ 
+/* use to attempt to fill the read buffer up to requested number of bytes */ 
+static int fill_buffer(URL_FILE *file, size_t want)
+{
+  fd_set fdread;
+  fd_set fdwrite;
+  fd_set fdexcep;
+  struct timeval timeout;
+  int rc;
+ 
+  /* only attempt to fill buffer if transactions still running and buffer
+   * doesnt exceed required size already
+   */ 
+  if((!file->still_running) || (file->buffer_pos > want))
+    return 0;
+ 
+  /* attempt to fill buffer */ 
+  do {
+    int maxfd = -1;
+    long curl_timeo = -1;
+ 
+    FD_ZERO(&fdread);
+    FD_ZERO(&fdwrite);
+    FD_ZERO(&fdexcep);
+ 
+    /* set a suitable timeout to fail on */ 
+    timeout.tv_sec = 60; /* 1 minute */ 
+    timeout.tv_usec = 0;
+ 
+    curl_multi_timeout(multi_handle, &curl_timeo);
+    if(curl_timeo >= 0) {
+      timeout.tv_sec = curl_timeo / 1000;
+      if(timeout.tv_sec > 1)
+        timeout.tv_sec = 1;
+      else
+        timeout.tv_usec = (curl_timeo % 1000) * 1000;
+    }
+ 
+    /* get file descriptors from the transfers */ 
+    curl_multi_fdset(multi_handle, &fdread, &fdwrite, &fdexcep, &maxfd);
+ 
+    /* In a real-world program you OF COURSE check the return code of the
+       function calls.  On success, the value of maxfd is guaranteed to be
+       greater or equal than -1.  We call select(maxfd + 1, ...), specially
+       in case of (maxfd == -1), we call select(0, ...), which is basically
+       equal to sleep. */ 
+ 
+    rc = select(maxfd+1, &fdread, &fdwrite, &fdexcep, &timeout);
+ 
+    switch(rc) {
+    case -1:
+      /* select error */ 
+      break;
+ 
+    case 0:
+    default:
+      /* timeout or readable/writable sockets */ 
+      curl_multi_perform(multi_handle, &file->still_running);
+      break;
+    }
+  } while(file->still_running && (file->buffer_pos < want));
+  return 1;
+}
+ 
+/* use to remove want bytes from the front of a files buffer */ 
+static int use_buffer(URL_FILE *file,int want)
+{
+  /* sort out buffer */ 
+  if((file->buffer_pos - want) <=0) {
+    /* ditch buffer - write will recreate */ 
+    if(file->buffer)
+      free(file->buffer);
+ 
+    file->buffer=NULL;
+    file->buffer_pos=0;
+    file->buffer_len=0;
+  }
+  else {
+    /* move rest down make it available for later */ 
+    memmove(file->buffer,
+            &file->buffer[want],
+            (file->buffer_pos - want));
+ 
+    file->buffer_pos -= want;
+  }
+  return 0;
+}
+ 
+URL_FILE *url_fopen(const char *url,const char *operation)
+{
+  /* this code could check for URLs or types in the 'url' and
+     basicly use the real fopen() for standard files */ 
+ 
+  URL_FILE *file;
+  (void)operation;
+ 
+  file = (URL_FILE*)malloc(sizeof(URL_FILE));
+  if(!file)
+    return NULL;
+ 
+  memset(file, 0, sizeof(URL_FILE));
+ 
+  if((file->handle.file=fopen(url,operation)))
+    file->type = CFTYPE_FILE; /* marked as URL */ 
+ 
+  else {
+    file->type = CFTYPE_CURL; /* marked as URL */ 
+    file->handle.curl = curl_easy_init();
+ 
+    curl_easy_setopt(file->handle.curl, CURLOPT_URL, url);
+    curl_easy_setopt(file->handle.curl, CURLOPT_WRITEDATA, file);
+    curl_easy_setopt(file->handle.curl, CURLOPT_VERBOSE, 0L);
+    curl_easy_setopt(file->handle.curl, CURLOPT_WRITEFUNCTION, write_callback);
+ 
+    if(!multi_handle)
+      multi_handle = curl_multi_init();
+ 
+    curl_multi_add_handle(multi_handle, file->handle.curl);
+ 
+    /* lets start the fetch */ 
+    curl_multi_perform(multi_handle, &file->still_running);
+ 
+    if((file->buffer_pos == 0) && (!file->still_running)) {
+      /* if still_running is 0 now, we should return NULL */ 
+ 
+      /* make sure the easy handle is not in the multi handle anymore */ 
+      curl_multi_remove_handle(multi_handle, file->handle.curl);
+ 
+      /* cleanup */ 
+      curl_easy_cleanup(file->handle.curl);
+ 
+      free(file);
+ 
+      file = NULL;
+    }
+  }
+  return file;
+}
+ 
+int url_fclose(URL_FILE *file)
+{
+  int ret=0;/* default is good return */ 
+ 
+  switch(file->type) {
+  case CFTYPE_FILE:
+    ret=fclose(file->handle.file); /* passthrough */ 
+    break;
+ 
+  case CFTYPE_CURL:
+    /* make sure the easy handle is not in the multi handle anymore */ 
+    curl_multi_remove_handle(multi_handle, file->handle.curl);
+ 
+    /* cleanup */ 
+    curl_easy_cleanup(file->handle.curl);
+    break;
+ 
+  default: /* unknown or supported type - oh dear */ 
+    ret=EOF;
+    errno=EBADF;
+    break;
+  }
+ 
+  if(file->buffer)
+    free(file->buffer);/* free any allocated buffer space */ 
+ 
+  free(file);
+ 
+  return ret;
+}
+ 
+int url_feof(URL_FILE *file)
+{
+  int ret=0;
+ 
+  switch(file->type) {
+  case CFTYPE_FILE:
+    ret=feof(file->handle.file);
+    break;
+ 
+  case CFTYPE_CURL:
+    if((file->buffer_pos == 0) && (!file->still_running))
+      ret = 1;
+    break;
+ 
+  default: /* unknown or supported type - oh dear */ 
+    ret=-1;
+    errno=EBADF;
+    break;
+  }
+  return ret;
+}
+ 
+size_t url_fread(void *ptr, size_t size, size_t nmemb, URL_FILE *file)
+{
+  size_t want;
+ 
+  switch(file->type) {
+  case CFTYPE_FILE:
+    want=fread(ptr,size,nmemb,file->handle.file);
+    break;
+ 
+  case CFTYPE_CURL:
+    want = nmemb * size;
+ 
+    fill_buffer(file,want);
+ 
+    /* check if theres data in the buffer - if not fill_buffer()
+     * either errored or EOF */ 
+    if(!file->buffer_pos)
+      return 0;
+ 
+    /* ensure only available data is considered */ 
+    if(file->buffer_pos < want)
+      want = file->buffer_pos;
+ 
+    /* xfer data to caller */ 
+    memcpy(ptr, file->buffer, want);
+ 
+    use_buffer(file,want);
+ 
+    want = want / size;     /* number of items */ 
+    break;
+ 
+  default: /* unknown or supported type - oh dear */ 
+    want=0;
+    errno=EBADF;
+    break;
+ 
+  }
+  return want;
+}
+ 
+char *url_fgets(char *ptr, size_t size, URL_FILE *file)
+{
+  size_t want = size - 1;/* always need to leave room for zero termination */ 
+  size_t loop;
+ 
+  switch(file->type) {
+  case CFTYPE_FILE:
+    ptr = fgets(ptr,size,file->handle.file);
+    break;
+ 
+  case CFTYPE_CURL:
+    fill_buffer(file,want);
+ 
+    /* check if theres data in the buffer - if not fill either errored or
+     * EOF */ 
+    if(!file->buffer_pos)
+      return NULL;
+ 
+    /* ensure only available data is considered */ 
+    if(file->buffer_pos < want)
+      want = file->buffer_pos;
+ 
+    /*buffer contains data */ 
+    /* look for newline or eof */ 
+    for(loop=0;loop < want;loop++) {
+      if(file->buffer[loop] == '\n') {
+        want=loop+1;/* include newline */ 
+        break;
+      }
+    }
+ 
+    /* xfer data to caller */ 
+    memcpy(ptr, file->buffer, want);
+    ptr[want]=0;/* allways null terminate */ 
+ 
+    use_buffer(file,want);
+ 
+    break;
+ 
+  default: /* unknown or supported type - oh dear */ 
+    ptr=NULL;
+    errno=EBADF;
+    break;
+  }
+ 
+  return ptr;/*success */ 
+}
+ 
+void url_rewind(URL_FILE *file)
+{
+  switch(file->type) {
+  case CFTYPE_FILE:
+    rewind(file->handle.file); /* passthrough */ 
+    break;
+ 
+  case CFTYPE_CURL:
+    /* halt transaction */ 
+    curl_multi_remove_handle(multi_handle, file->handle.curl);
+ 
+    /* restart */ 
+    curl_multi_add_handle(multi_handle, file->handle.curl);
+ 
+    /* ditch buffer - write will recreate - resets stream pos*/ 
+    if(file->buffer)
+      free(file->buffer);
+ 
+    file->buffer=NULL;
+    file->buffer_pos=0;
+    file->buffer_len=0;
+ 
+    break;
+ 
+  default: /* unknown or supported type - oh dear */ 
+    break;
+  }
+}
+
 }
\ No newline at end of file