StreamFilter.cpp

00001 /**
00002  * =============================================================================
00003  * Stream filter for Twitter.
00004  * http://mbed.org/users/shintamainjp/notebook/starboard_expbrd-one_ex1_en/
00005  * =============================================================================
00006  * Copyright (c) 2010 Shinichiro Nakamura (CuBeatSystems)
00007  *
00008  * Permission is hereby granted, free of charge, to any person obtaining a copy
00009  * of this software and associated documentation files (the "Software"), to deal
00010  * in the Software without restriction, including without limitation the rights
00011  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
00012  * copies of the Software, and to permit persons to whom the Software is
00013  * furnished to do so, subject to the following conditions:
00014  *
00015  * The above copyright notice and this permission notice shall be included in
00016  * all copies or substantial portions of the Software.
00017  *
00018  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
00019  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
00020  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
00021  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
00022  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
00023  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
00024  * THE SOFTWARE.
00025  * =============================================================================
00026  */
00027 
00028 #include "StreamFilter.h"
00029 
00030 /**
00031  * Create.
00032  *
00033  * @param headtxt Head of a target.
00034  * @param tailtxt Tail of a target.
00035  */
00036 StreamFilter::StreamFilter(const char *headtxt, const char *tailtxt)
00037         : headcnt(0), tailcnt(0), head(headtxt), tail(tailtxt), content("") {
00038 }
00039 
00040 /**
00041  * Dispose.
00042  */
00043 StreamFilter::~StreamFilter() {
00044 }
00045 
00046 /**
00047  * Check state of done.
00048  *
00049  * @return Return true if it done.
00050  */
00051 bool StreamFilter::done() {
00052     if ((headcnt == strlen(head)) && (tailcnt == strlen(tail))) {
00053         return true;
00054     }
00055     return false;
00056 }
00057 
00058 /**
00059  * Reset state.
00060  */
00061 void StreamFilter::reset() {
00062     headcnt = 0;
00063     tailcnt = 0;
00064     memset(content, 0, sizeof(content));
00065 }
00066 
00067 /**
00068  * Push a data to a internal buffer.
00069  *
00070  * @param c character.
00071  */
00072 void StreamFilter::push(char c) {
00073     if (done()) {
00074         return;
00075     }
00076 
00077     /*
00078      * Check a text for the header.
00079      */
00080     if (headcnt < strlen(head)) {
00081         if (c == head[headcnt]) {
00082             headcnt++;
00083         } else {
00084             headcnt = 0;
00085         }
00086         return;
00087     }
00088     /*
00089      * Check a text for the tailer.
00090      */
00091     if (tailcnt < strlen(tail)) {
00092         if (c == tail[tailcnt]) {
00093             tailcnt++;
00094             return;
00095         } else {
00096             tailcnt = 0;
00097         }
00098     }
00099     /*
00100      * It's a content.
00101      */
00102     const int n = strlen(content);
00103     if (n < sizeof(content) - 1) {
00104         content[n + 0] = c;
00105         content[n + 1] = '\0';
00106     }
00107 }
00108 
00109 /**
00110  * Get a content text.
00111  *
00112  * @param buf A pointer to a buffer.
00113  * @param bufsiz Size of the buffer.
00114  *
00115  * @return true if it succeed.
00116  */
00117 bool StreamFilter::getContent(char *buf, size_t bufsiz) {
00118     if (strlen(content) < bufsiz) {
00119         strcpy(buf, content);
00120         return true;
00121     }
00122     return false;
00123 }