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Diffstat (limited to 'src/uscxml/Utilities.cpp')
| -rw-r--r-- | src/uscxml/Utilities.cpp | 402 |
1 files changed, 402 insertions, 0 deletions
diff --git a/src/uscxml/Utilities.cpp b/src/uscxml/Utilities.cpp new file mode 100644 index 0000000..04a376c --- /dev/null +++ b/src/uscxml/Utilities.cpp @@ -0,0 +1,402 @@ +/***************************************************************************** + * + * Taken in its entirety from http://curl.haxx.se/libcurl/c/fopen.html + * + * This example source code introduces a c library buffered I/O interface to + * URL reads it supports fopen(), fread(), fgets(), feof(), fclose(), + * rewind(). Supported functions have identical prototypes to their normal c + * lib namesakes and are preceaded by url_ . + * + * Using this code you can replace your program's fopen() with url_fopen() + * and fread() with url_fread() and it become possible to read remote streams + * instead of (only) local files. Local files (ie those that can be directly + * fopened) will drop back to using the underlying clib implementations + * + * See the main() function at the bottom that shows an app that retrives from a + * specified url using fgets() and fread() and saves as two output files. + * + * Copyright (c) 2003 Simtec Electronics + * + * Re-implemented by Vincent Sanders <vince@kyllikki.org> with extensive + * reference to original curl example code + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. The name of the author may not be used to endorse or promote products + * derived from this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR + * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES + * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. + * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, + * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT + * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, + * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY + * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF + * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + * + * This example requires libcurl 7.9.7 or later. + */ + +#include <stdio.h> +#include <string.h> +#ifndef WIN32 +#include <sys/time.h> +#endif +#include <stdlib.h> +#include <errno.h> + +#include "uscxml/Utilities.h" + +/* 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; + } +} +
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