diff options
Diffstat (limited to 'src/buffer.c')
| -rw-r--r-- | src/buffer.c | 111 |
1 files changed, 54 insertions, 57 deletions
diff --git a/src/buffer.c b/src/buffer.c index d051905..bbb12a0 100644 --- a/src/buffer.c +++ b/src/buffer.c @@ -1,4 +1,4 @@ -/* $Id: buffer.c,v 1.14 2001-10-25 04:39:10 rjkaes Exp $ +/* $Id: buffer.c,v 1.15 2001-11-05 15:23:05 rjkaes Exp $ * * The buffer used in each connection is a linked list of lines. As the lines * are read in and written out the buffer expands and contracts. Basically, @@ -27,8 +27,8 @@ #include "log.h" #include "utils.h" -#define BUFFER_HEAD(x) (((struct buffer_s *)(x))->head) -#define BUFFER_TAIL(x) (((struct buffer_s *)(x))->tail) +#define BUFFER_HEAD(x) (x)->head +#define BUFFER_TAIL(x) (x)->tail struct bufline_s { unsigned char *string; /* the actual string of data */ @@ -37,31 +37,18 @@ struct bufline_s { size_t pos; /* start sending from this offset */ }; -struct buffer_s { - struct bufline_s *head; /* top of the buffer */ - struct bufline_s *tail; /* bottom of the buffer */ - size_t size; /* total size of the buffer */ -}; - -/* - * Return the size of the supplied buffer. - */ -size_t buffer_size(struct buffer_s *buffptr) -{ - assert(buffptr != NULL); - - return buffptr->size; -} - /* * Take a string of data and a length and make a new line which can be added - * to the buffer + * to the buffer. We don't make a copy of the data, but simply copy the + * pointer into the structure. In other words, when you insert data into the + * buffer, the buffer becomes responsible for freeing it. */ static struct bufline_s *makenewline(unsigned char *data, size_t length) { struct bufline_s *newline; assert(data != NULL); + assert(length > 0); if (!(newline = safemalloc(sizeof(struct bufline_s)))) return NULL; @@ -69,6 +56,8 @@ static struct bufline_s *makenewline(unsigned char *data, size_t length) newline->string = data; newline->next = NULL; newline->length = length; + + /* Position our "read" pointer at the beginning of the data */ newline->pos = 0; return newline; @@ -100,8 +89,13 @@ struct buffer_s *new_buffer(void) if (!(buffptr = safemalloc(sizeof(struct buffer_s)))) return NULL; - buffptr->head = buffptr->tail = NULL; - buffptr->size = 0; + /* + * Since the buffer is initially empty, set the HEAD and TAIL + * pointers to NULL since they can't possibly point anywhere at the + * moment. + */ + BUFFER_HEAD(buffptr) = BUFFER_TAIL(buffptr) = NULL; + BUFFER_SIZE(buffptr) = 0; return buffptr; } @@ -120,8 +114,6 @@ void delete_buffer(struct buffer_s *buffptr) free_line(BUFFER_HEAD(buffptr)); BUFFER_HEAD(buffptr) = next; } - BUFFER_HEAD(buffptr) = NULL; - BUFFER_TAIL(buffptr) = NULL; safefree(buffptr); } @@ -136,43 +128,46 @@ static int add_to_buffer(struct buffer_s *buffptr, unsigned char *data, assert(buffptr != NULL); assert(data != NULL); + assert(length > 0); + + /* + * Sanity check here. A buffer with a non-NULL head pointer must + * have a size greater than zero, and vice-versa. + */ + if (BUFFER_HEAD(buffptr) == NULL) + assert(BUFFER_SIZE(buffptr) == 0); + else + assert(BUFFER_SIZE(buffptr) > 0); + /* + * Make a new line so we can add it to the buffer. + */ if (!(newline = makenewline(data, length))) return -1; - if (!BUFFER_HEAD(buffptr) && !BUFFER_TAIL(buffptr)) + if (BUFFER_SIZE(buffptr) == 0) BUFFER_HEAD(buffptr) = BUFFER_TAIL(buffptr) = newline; else BUFFER_TAIL(buffptr) = (BUFFER_TAIL(buffptr)->next = newline); - buffptr->size += length; + BUFFER_SIZE(buffptr) += length; return 0; } /* - * Shift a line off the top of the buffer (remove the line from the top of - * the buffer) + * Remove the first line from the top of the buffer */ static struct bufline_s *remove_from_buffer(struct buffer_s *buffptr) { struct bufline_s *line; assert(buffptr != NULL); - - if (!BUFFER_HEAD(buffptr) && !BUFFER_TAIL(buffptr)) { - line = BUFFER_HEAD(buffptr); - BUFFER_HEAD(buffptr) = BUFFER_TAIL(buffptr) = NULL; - buffptr->size = 0; - return line; - } + assert(BUFFER_HEAD(buffptr) != NULL); line = BUFFER_HEAD(buffptr); BUFFER_HEAD(buffptr) = line->next; - if (!BUFFER_HEAD(buffptr)) - BUFFER_TAIL(buffptr) = NULL; - buffptr->size -= line->length; return line; @@ -192,14 +187,14 @@ ssize_t readbuff(int fd, struct buffer_s *buffptr) assert(fd >= 0); assert(buffptr != NULL); - if (buffer_size(buffptr) >= READ_BUFFER_SIZE) + if (BUFFER_SIZE(buffptr) >= READ_BUFFER_SIZE) return 0; buffer = safemalloc(READ_BUFFER_SIZE); if (!buffer) return 0; - bytesin = read(fd, buffer, READ_BUFFER_SIZE - buffer_size(buffptr)); + bytesin = read(fd, buffer, READ_BUFFER_SIZE - BUFFER_SIZE(buffptr)); if (bytesin > 0) { newbuffer = saferealloc(buffer, bytesin); @@ -214,26 +209,26 @@ ssize_t readbuff(int fd, struct buffer_s *buffptr) } return bytesin; - } else if (bytesin == 0) { - /* connection was closed by client */ - safefree(buffer); - return -1; } else { - switch (errno) { + safefree(buffer); + if (bytesin == 0) { + /* connection was closed by client */ + return -1; + } else { + switch (errno) { #ifdef EWOULDBLOCK - case EWOULDBLOCK: + case EWOULDBLOCK: #else # ifdef EAGAIN - case EAGAIN: + case EAGAIN: # endif #endif - case EINTR: - safefree(buffer); - return 0; - default: - log_message(LOG_ERR, "readbuff: recv() error \"%s\" on file descriptor %d", strerror(errno), fd); - safefree(buffer); - return -1; + case EINTR: + return 0; + default: + log_message(LOG_ERR, "readbuff: recv() error \"%s\" on file descriptor %d", strerror(errno), fd); + return -1; + } } } } @@ -250,11 +245,13 @@ ssize_t writebuff(int fd, struct buffer_s *buffptr) assert(fd >= 0); assert(buffptr != NULL); - line = BUFFER_HEAD(buffptr); - - if (buffer_size(buffptr) <= 0) + if (BUFFER_SIZE(buffptr) == 0) return 0; + /* Sanity check. It would be bad to be using a NULL pointer! */ + assert(BUFFER_HEAD(buffptr) != NULL); + + line = BUFFER_HEAD(buffptr); bytessent = write(fd, line->string + line->pos, line->length - line->pos); if (bytessent >= 0) { |