root / trunk / code / projects / colonet / ColonetServer / ConnectionPool.cpp @ 161
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1 | 11 | emarinel | /**
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2 | 29 | jknichel | * @file ConnectionPool.cpp
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3 | *
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4 | 11 | emarinel | * @author Jason Knichel
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5 | * @date 7/22/07
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6 | 144 | jknichel | *
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7 | 11 | emarinel | */
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8 | |||
9 | #include <sys/select.h> |
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10 | #include <ctype.h> |
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11 | #include <errno.h> |
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12 | #include <unistd.h> |
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13 | #include <string.h> |
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14 | #include <stdlib.h> |
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15 | #include <stdio.h> |
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16 | |||
17 | #include "includes/ConnectionPool.h" |
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18 | 128 | jknichel | #include "includes/Command.h" |
19 | 11 | emarinel | #include "../lib/colonet_defs.h" |
20 | 161 | emarinel | |
21 | 118 | emarinel | #include <colonet_wireless.h> |
22 | 11 | emarinel | |
23 | 29 | jknichel | /**
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24 | * @brief The default constructor for ConnectionPool
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25 | */
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26 | 11 | emarinel | ConnectionPool::ConnectionPool() { |
27 | max_file_descriptor = 0;
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28 | next_available_slot = 0;
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29 | number_clients_ready = 0;
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30 | |||
31 | FD_ZERO(&ready_set); |
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32 | FD_ZERO(&read_set); |
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33 | FD_ZERO(&write_set); |
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34 | |||
35 | memset(&client_file_descriptor_array, 0, sizeof(int)*MAX_CONNECTIONS); |
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36 | memset(&read_buffer, 0, sizeof(char *)*MAX_CONNECTIONS); |
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37 | memset(&read_buffer_size, 0, sizeof(int)*MAX_CONNECTIONS); |
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38 | memset(&write_buffer, 0, sizeof(char *)*MAX_CONNECTIONS); |
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39 | memset(&write_buffer_size, 0, sizeof(int)*MAX_CONNECTIONS); |
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40 | } |
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41 | |||
42 | 29 | jknichel | /**
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43 | * @brief The destructor for ConnectionPool
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44 | */
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45 | 11 | emarinel | ConnectionPool::~ConnectionPool() { |
46 | } |
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47 | |||
48 | 29 | jknichel | /**
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49 | * @brief Adds a client to the connection pool
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50 | *
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51 | * @param client_file_descriptor The file descriptor to add to the connection pool
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52 | *
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53 | * @return 0 on success, negative error code on failure
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54 | */
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55 | 11 | emarinel | int ConnectionPool::add_client(int client_file_descriptor) { |
56 | if (client_file_descriptor < 0) { |
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57 | return ERROR_INVALID_CLIENT_DESCRIPTOR;
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58 | } |
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59 | |||
60 | if (next_available_slot == MAX_CONNECTIONS) {
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61 | return ERROR_TOO_MANY_CLIENTS;
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62 | } |
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63 | |||
64 | if (client_file_descriptor > max_file_descriptor) {
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65 | max_file_descriptor = client_file_descriptor; |
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66 | } |
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67 | |||
68 | FD_SET(client_file_descriptor, &ready_set); |
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69 | |||
70 | int next_slot = next_available_slot;
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71 | |||
72 | client_file_descriptor_array[next_slot] = client_file_descriptor; |
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73 | read_buffer[next_slot] = (char*) malloc(sizeof(char) * READ_BUFFER_SIZE); |
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74 | if (!(read_buffer[next_slot])) {
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75 | return ERROR_ALLOCATING_MEMORY;
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76 | } |
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77 | read_buffer_size[next_slot] = 0;
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78 | write_buffer[next_slot] = (char *)malloc(sizeof(char) * WRITE_BUFFER_SIZE); |
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79 | |||
80 | if (!(write_buffer[next_slot])) {
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81 | free(read_buffer[next_slot]); |
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82 | return ERROR_ALLOCATING_MEMORY;
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83 | } |
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84 | |||
85 | write_buffer_size[next_slot] = 0;
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86 | |||
87 | next_available_slot++; |
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88 | |||
89 | return 0; |
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90 | } |
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91 | |||
92 | 29 | jknichel | /**
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93 | * @brief Removes a client from the connection pool
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94 | *
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95 | * @param The index in the pool of the client to remove
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96 | *
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97 | * @return 0 on success, negative error code on failure
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98 | */
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99 | 27 | jknichel | int ConnectionPool::remove_client(int pool_index) { |
100 | if (pool_index < 0 || pool_index >= next_available_slot) { |
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101 | 11 | emarinel | return ERROR_INVALID_CLIENT_DESCRIPTOR;
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102 | } |
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103 | |||
104 | 27 | jknichel | int client_file_descriptor = client_file_descriptor_array[pool_index];
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105 | 11 | emarinel | |
106 | 27 | jknichel | if (FD_ISSET(client_file_descriptor, &ready_set)) {
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107 | FD_CLR(client_file_descriptor, &ready_set); |
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108 | 11 | emarinel | } |
109 | 27 | jknichel | if (FD_ISSET(client_file_descriptor, &read_set)) {
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110 | FD_CLR(client_file_descriptor, &read_set); |
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111 | 11 | emarinel | } |
112 | 27 | jknichel | if (FD_ISSET(client_file_descriptor, &write_set)) {
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113 | FD_CLR(client_file_descriptor, &write_set); |
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114 | 11 | emarinel | } |
115 | |||
116 | 27 | jknichel | free(read_buffer[pool_index]); |
117 | free(write_buffer[pool_index]); |
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118 | for (int j = pool_index; j < next_available_slot - 1; j++) { |
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119 | client_file_descriptor_array[pool_index] = client_file_descriptor_array[pool_index+1];
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120 | read_buffer[pool_index] = read_buffer[pool_index+1];
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121 | read_buffer_size[pool_index] = read_buffer_size[pool_index+1];
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122 | write_buffer[pool_index] = write_buffer[pool_index+1];
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123 | write_buffer_size[pool_index] = write_buffer_size[pool_index+1];
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124 | 11 | emarinel | } |
125 | next_available_slot--; |
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126 | int temp_max_file_descriptor = 0; |
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127 | |||
128 | for (int j = 0; j < next_available_slot; j++) { |
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129 | if (client_file_descriptor_array[j] > temp_max_file_descriptor)
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130 | temp_max_file_descriptor = client_file_descriptor_array[j]; |
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131 | } |
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132 | max_file_descriptor = temp_max_file_descriptor; |
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133 | |||
134 | printf("Removing client.\n");
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135 | |||
136 | return 0; |
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137 | } |
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138 | |||
139 | 29 | jknichel | /**
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140 | * @brief Checks the status of the clients
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141 | *
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142 | * Sees is any clients are ready to read from their file descriptor or are
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143 | * ready to write to their file descriptor.
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144 | *
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145 | * @return 0 on success, negative error code on error
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146 | */
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147 | 11 | emarinel | //TODO: test that it drops commands properly if it gets sent too much data
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148 | // do we want it to drop the data or drop the connection?
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149 | 118 | emarinel | int ConnectionPool::check_clients() {
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150 | 11 | emarinel | int i;
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151 | |||
152 | for (i = 0; i < next_available_slot; i++) { |
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153 | 145 | jknichel | int client_file_descriptor = client_file_descriptor_array[i];
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154 | 11 | emarinel | |
155 | if (FD_ISSET(client_file_descriptor, &read_set)) {
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156 | 145 | jknichel | if (read_data(i, client_file_descriptor) == DECREMENT_INDEX_COUNTER) {
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157 | i--; |
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158 | continue;
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159 | 11 | emarinel | } |
160 | } |
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161 | |||
162 | if (FD_ISSET(client_file_descriptor, &write_set)) {
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163 | 145 | jknichel | write_data(i, client_file_descriptor); |
164 | 11 | emarinel | } |
165 | } |
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166 | |||
167 | return 0; |
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168 | } |
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169 | |||
170 | 29 | jknichel | /**
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171 | * @brief Puts text into a write buffer that will be written to a client's file
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172 | * descriptor sometime when the client is ready to write.
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173 | *
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174 | * @param pool_index Index in the pool of the client to write to
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175 | * @param message The message to be written
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176 | * @param length The length of the message
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177 | *
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178 | * @return 0 on success, negative error code on failure
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179 | */
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180 | 14 | jknichel | int ConnectionPool::write_to_client(int pool_index, char * message, int length) { |
181 | 22 | jknichel | if (pool_index < 0 || pool_index >= next_available_slot) { |
182 | return ERROR_INVALID_CLIENT_ID;
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183 | } |
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184 | |||
185 | if (!message) {
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186 | return ERROR_INVALID_MESSAGE;
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187 | } |
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188 | |||
189 | if (length < 0) { |
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190 | return ERROR_INVALID_MESSAGE_LENGTH;
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191 | } |
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192 | |||
193 | 34 | emarinel | if (length > (WRITE_BUFFER_SIZE-write_buffer_size[pool_index])) {
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194 | //TODO: make this a logging statement instead of a print statement
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195 | printf("There is not enough room in the write buffer to send the data to the client.\n");
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196 | return ERROR_NOT_ENOUGH_ROOM;
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197 | } |
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198 | 11 | emarinel | |
199 | 14 | jknichel | memcpy(write_buffer[pool_index], message, length); |
200 | write_buffer_size[pool_index] += length; |
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201 | |||
202 | return 0; |
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203 | } |
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204 | |||
205 | 29 | jknichel | /**
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206 | * @brief Sets the socket to listen on
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207 | *
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208 | * @param listen_socket The socket to listen on
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209 | *
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210 | * @return void
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211 | */
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212 | 143 | jknichel | void ConnectionPool::add_new_socket_to_pool(int new_socket) { |
213 | if (new_socket < 0) |
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214 | 58 | jknichel | return;
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215 | |||
216 | 143 | jknichel | FD_SET(new_socket, &ready_set); |
217 | |||
218 | if (new_socket > max_file_descriptor) {
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219 | max_file_descriptor = new_socket; |
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220 | } |
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221 | 11 | emarinel | } |
222 | |||
223 | 29 | jknichel | /**
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224 | * @brief Find out what file descriptors are ready to write to and read from
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225 | *
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226 | * @param listen_socket The socket to listen on
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227 | * @param select_timeout The timeout for the select statement
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228 | *
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229 | * @return 0
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230 | */
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231 | 58 | jknichel | int ConnectionPool::perform_select(int listen_socket) { |
232 | 11 | emarinel | read_set = ready_set; |
233 | write_set = ready_set; |
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234 | |||
235 | 58 | jknichel | struct timeval select_timeout;
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236 | memset(&select_timeout, 0, sizeof(select_timeout)); |
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237 | |||
238 | 11 | emarinel | //TODO(Jason): think about why I put this there
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239 | if (max_file_descriptor < listen_socket)
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240 | max_file_descriptor = listen_socket; |
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241 | |||
242 | 58 | jknichel | number_clients_ready = select(max_file_descriptor+1, &(read_set), &(write_set), NULL, &select_timeout); |
243 | 11 | emarinel | |
244 | 59 | jknichel | if (number_clients_ready < 0) { |
245 | perror(__FUNCTION__); |
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246 | } |
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247 | |||
248 | 11 | emarinel | return 0; |
249 | } |
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250 | |||
251 | int ConnectionPool::is_socket_ready_to_read(int socket) { |
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252 | return FD_ISSET(socket, &read_set);
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253 | } |
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254 | |||
255 | int ConnectionPool::get_number_clients_ready() {
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256 | return number_clients_ready;
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257 | } |
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258 | |||
259 | |||
260 | 145 | jknichel | int ConnectionPool::read_data(int pool_index, int client_file_descriptor) { |
261 | char temporary_buffer[READ_BUFFER_SIZE];
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262 | char temporary_command_buffer[READ_BUFFER_SIZE+1]; |
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263 | int num_bytes_read;
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264 | int length;
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265 | int command_length;
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266 | |||
267 | num_bytes_read = read(client_file_descriptor, temporary_buffer, READ_BUFFER_SIZE); |
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268 | |||
269 | if (num_bytes_read == 0 || (num_bytes_read == -1 && errno == ECONNRESET)) { |
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270 | remove_client(pool_index); |
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271 | return DECREMENT_INDEX_COUNTER;
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272 | } |
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273 | |||
274 | while (num_bytes_read > 0) { |
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275 | length = num_bytes_read; |
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276 | |||
277 | if (length + read_buffer_size[pool_index] > READ_BUFFER_SIZE) {
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278 | length = READ_BUFFER_SIZE - read_buffer_size[pool_index]; |
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279 | } |
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280 | |||
281 | memcpy(read_buffer[pool_index]+read_buffer_size[pool_index], temporary_buffer, length); |
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282 | read_buffer_size[pool_index] += length; |
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283 | num_bytes_read -= length; |
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284 | |||
285 | if (num_bytes_read > 0) { |
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286 | memmove(temporary_buffer, temporary_buffer+length, READ_BUFFER_SIZE - length); |
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287 | } |
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288 | |||
289 | printf("Read buffer is %s\n", read_buffer[pool_index]);
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290 | |||
291 | char* newline_position;
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292 | |||
293 | while ((newline_position = strstr(read_buffer[pool_index], "\n"))) { |
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294 | |||
295 | 161 | emarinel | //if no newline if found in the entire readbuffer (when its full),
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296 | 145 | jknichel | //toss out the command
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297 | // because either the command being given is too long or someone is trying
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298 | // to do something bad to the server
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299 | //TODO: this is from before all this code was put in the loop. reconsider
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300 | // how to check this error condition and do it elsewhere
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301 | if (!newline_position && (read_buffer_size[pool_index] == READ_BUFFER_SIZE)) {
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302 | read_buffer_size[pool_index] = 0;
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303 | break;
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304 | } |
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305 | |||
306 | //if no newline is found then there is not a command in the buffer
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307 | if (!newline_position) {
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308 | break;
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309 | } |
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310 | |||
311 | command_length = (newline_position - read_buffer[pool_index])+1;
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312 | |||
313 | //the newline was found in garbage in the currently not used portion
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314 | // of the read buffer
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315 | if (command_length > read_buffer_size[pool_index]) {
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316 | break;
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317 | } |
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318 | |||
319 | memcpy(temporary_command_buffer, read_buffer[pool_index], command_length); |
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320 | //do command_length-1 to get rid of the newline terminating the command
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321 | temporary_command_buffer[command_length-1] = '\0'; |
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322 | //did this because telnet was putting a \r\n on the end instead of just \n
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323 | if (isspace(temporary_command_buffer[command_length-2])) { |
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324 | temporary_command_buffer[command_length-2] = '\0'; |
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325 | } |
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326 | |||
327 | memmove(read_buffer[pool_index], read_buffer[pool_index]+command_length, read_buffer_size[pool_index] - command_length); |
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328 | read_buffer_size[pool_index] -= command_length; |
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329 | |||
330 | if (command_length > MAX_COMMAND_LEN) {
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331 | printf("The command was too long. Tossing command out.\n");
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332 | break;
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333 | } |
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334 | |||
335 | Command command(this);
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336 | if (command.parse_command(temporary_command_buffer, pool_index) < 0) { |
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337 | printf("There was an error parsing command\n");
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338 | break;
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339 | } |
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340 | } |
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341 | } |
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342 | |||
343 | return 0; |
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344 | } |
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345 | |||
346 | |||
347 | int ConnectionPool::write_data(int pool_index, int client_file_descriptor) { |
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348 | if (write_buffer_size[pool_index] == 0) { |
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349 | return 0; |
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350 | } |
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351 | |||
352 | int sent = write(client_file_descriptor, write_buffer[pool_index], write_buffer_size[pool_index]);
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353 | memmove(write_buffer[pool_index], write_buffer[pool_index]+sent, WRITE_BUFFER_SIZE - sent); |
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354 | 161 | emarinel | write_buffer_size[pool_index] -= sent; |
355 | 145 | jknichel | |
356 | return 0; |
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357 | } |