email plugin: Do not allocate memory for the return value in read_line ().

The read_line () function now uses the provided buffer to save the return
value to. In case no complete line could be read, read_line () is called
recursively until '\n' has been found or end-of-file has been reached.

Signed-off-by: Sebastian Harl <sh@tokkee.org>

diff --git a/src/email.c b/src/email.c
index 401ac92..377a6b1 100644 (file)
--- a/src/email.c
+++ b/src/email.c
@@ -115,7 +115,8 @@ typedef struct conn {
 
        /* buffer to read data to */
        char *buffer;
-       int  idx; /* current position in buffer */
+       int  idx; /* current write position in buffer */
+       int  length; /* length of the current line, i.e. index of '\0' */
 
        struct conn *next;
 } conn_t;
@@ -322,8 +323,7 @@ char read_char (conn_t *src)
 /* Read a single line (terminated by '\n') from the the socket.
  *
  * The return value is zero terminated and does not contain any newline
- * characters. In case that no complete line is available (non-blocking mode
- * should be enabled) an empty string is returned.
+ * characters.
  *
  * If an error occurs or end-of-file is reached return NULL.
  *
@@ -333,10 +333,16 @@ char read_char (conn_t *src)
  * acceptable in this case ;-) */
 char *read_line (conn_t *src)
 {
-       int  i = 0;
-       char *ret;
+       int i = 0;
+
+       assert ((BUFSIZE >= src->idx) && (src->idx >= 0));
+       assert ((src->idx > src->length) || (src->length == 0));
 
-       assert (BUFSIZE > src->idx);
+       if (src->length > 0) { /* remove old line */
+               src->idx -= (src->length + 1);
+               memmove (src->buffer, src->buffer + src->length + 1, src->idx);
+               src->length = 0;
+       }
 
        for (i = 0; i < src->idx; ++i) {
                if ('\n' == src->buffer[i])
@@ -381,9 +387,7 @@ char *read_line (conn_t *src)
                }
 
                if (i == src->idx) {
-                       ret = (char *)smalloc (1);
-
-                       ret[0] = '\0';
+                       src->length = 0;
 
                        if (BUFSIZE == src->idx) { /* no space left in buffer */
                                while ('\n' != read_char (src))
@@ -391,21 +395,14 @@ char *read_line (conn_t *src)
 
                                src->idx = 0;
                        }
-                       return ret;
+                       return read_line (src);
                }
        }
 
-       ret = (char *)smalloc (i + 1);
-       memcpy (ret, src->buffer, i + 1);
-       ret[i] = '\0';
-
-       src->idx -= (i + 1);
+       src->buffer[i] = '\0';
+       src->length    = i;
 
-       if (0 == src->idx)
-               src->buffer[0] = '\0';
-       else
-               memmove (src->buffer, src->buffer + i + 1, src->idx);
-       return ret;
+       return src->buffer;
 } /* char *read_line (conn_t *) */
 
 static void *collect (void *arg)
@@ -438,6 +435,7 @@ static void *collect (void *arg)
 
                connection->buffer = buffer;
                connection->idx    = 0;
+               connection->length = 0;
 
                { /* put the socket in non-blocking mode */
                        int flags = 0;
@@ -463,14 +461,8 @@ static void *collect (void *arg)
                                break;
                        }
 
-                       if ('\0' == line[0]) {
-                               free (line);
-                               continue;
-                       }
-
                        if (':' != line[1]) {
                                syslog (LOG_ERR, "email: syntax error in line '%s'", line);
-                               free (line);
                                continue;
                        }
 
@@ -482,7 +474,6 @@ static void *collect (void *arg)
 
                                if (NULL == tmp) {
                                        syslog (LOG_ERR, "email: syntax error in line '%s'", line);
-                                       free (line);
                                        continue;
                                }
 
@@ -516,8 +507,6 @@ static void *collect (void *arg)
                        else {
                                syslog (LOG_ERR, "email: unknown type '%c'", line[0]);
                        }
-
-                       free (line);
                } /* while (loop) */
 
                close (connection->socket);