new realization of cancel download

src/client.c

@@ -5,6 +5,7 @@
 #include "file_p.h"
 #include "main.h"
 #include "session.h"
+#include "utils.h"
 #include <fcntl.h>
 #include <stdint.h>
 #include <stdio.h>
@@ -85,3 +86,17 @@ void process_client_command(char *line, session *sess, server_data_t *s_d) {
     session_send_string(sess, "OK. Bye!\n");
   }
 }
+
+void download_confirm(char *line, session *sess, server_data_t *s_d) {
+  if (!strncmp(line, "continue", sizeof "continue" - 1)) {
+    sess->state = OP_DOWNLOAD;
+    sess->file->package_rest = PACKAGE_SIZE;
+    return;
+  }
+  if (!strncmp(line, "cancel", sizeof "cancel" - 1)) {
+    print_log(stdout, pl_info, "Downloading of %s is canceled by the client\n",
+              sess->file->name);
+    clear_file_from_sess(sess);
+    sess->state = OP_WAIT;
+  }
+}

src/client.h

@@ -6,5 +6,5 @@
 
 #include "main.h"
 void process_client_command(char *line, session *sess, server_data_t *s_d);
-
+void download_confirm(char *line, session *sess, server_data_t *s_d);
 #endif

src/file_p.c

@@ -183,6 +183,7 @@ int32_t file_send_prepare(session *sess, char *line, server_data_t *s_d) {
 
   sess->file->rest = fsize;
   sess->fd = file_d;
+  sess->file->package_rest = PACKAGE_SIZE;
   return 0;
 }
 
@@ -294,7 +295,15 @@ void file_download(session *sess) {
   int source_d = sess->fd;
   int dest_d = sess->sd;
   char buf[INBUFSIZE];
-  int rlen = read(source_d, buf, INBUFSIZE);
+  int read_len;
+
+  if (sess->file->package_rest < INBUFSIZE) {
+    read_len = sess->file->package_rest;
+  } else {
+    read_len = INBUFSIZE;
+  }
+
+  int rlen = read(source_d, buf, read_len);
   if (rlen == 0) {
     if (sess->file->rest) {
       print_log(stdout, pl_error, "Error downloading file %s!\n",
@@ -312,11 +321,17 @@ void file_download(session *sess) {
     sess->state = ERR;
   }
   sess->file->rest -= rlen;
+  sess->file->package_rest -= rlen;
   if (!sess->file->rest) {
     print_log(stdout, pl_info, "File %s is downloaded from the server\n",
               sess->file->name);
     clear_file_from_sess(sess);
     sess->state = OP_WAIT;
+    return;
+  }
+
+  if (sess->file->package_rest == 0) {
+    sess->state = OP_DOWNLOAD_WAIT_CONFIRM_PACKAGE;
   }
 }
 

src/main.h

@@ -16,6 +16,7 @@
 #define FILE_DESCRIPTIONS_NAME "./file_descriptions"
 #define FILE_USER_LIST_NAME "userlist"
 #define WELCOME_FILE_NAME "welcome"
+#define PACKAGE_SIZE INBUFSIZE * 10
 
 #ifndef __USE_MISC
 #define __USE_MISC
@@ -31,6 +32,7 @@ enum sess_states {
   OP_WAIT,
   OP_UPLOAD,
   OP_UPLOAD_DESCRIPTION,
+  OP_DOWNLOAD_WAIT_CONFIRM_PACKAGE,
   ERR,
   FIN
 };

src/server.c

@@ -58,6 +58,9 @@ void server_main_loop(server_data_t *s_d) {
           maxfd = i;
         /* active uploads/downloads */
         if (connections[i]->fd > -1) {
+          if (connections[i]->state == OP_DOWNLOAD_WAIT_CONFIRM_PACKAGE) {
+            continue;
+          }
           int fd = connections[i]->fd;
           FD_SET(fd, &readfds);
           if (fd > maxfd)

src/session.c

@@ -211,6 +211,9 @@ void perform_session_action(session *sess, char *line, server_data_t *s_d) {
       }
     }
     break;
+  case OP_DOWNLOAD_WAIT_CONFIRM_PACKAGE:
+    download_confirm(line, sess, s_d);
+    break;
   }
   /* } */
 }