diff options
| -rw-r--r-- | src/vector.c | 46 | ||||
| -rw-r--r-- | src/vector.h | 10 |
2 files changed, 41 insertions, 15 deletions
diff --git a/src/vector.c b/src/vector.c index 7bb1d80..6638fbe 100644 --- a/src/vector.c +++ b/src/vector.c @@ -1,4 +1,4 @@ -/* $Id: vector.c,v 1.7 2003-05-29 20:47:52 rjkaes Exp $ +/* $Id: vector.c,v 1.8 2003-05-29 21:07:22 rjkaes Exp $ * * A vector implementation. The vector can be of an arbitrary length, and * the data for each entry is an lump of data (the size is stored in the @@ -101,16 +101,21 @@ vector_delete(vector_t vector) * collection of bytes of _len_ octets. The data is copied into the * vector, so the original data must be freed to avoid a memory leak. * The "data" must be non-NULL and the "len" must be greater than zero. + * "pos" is either 0 to prepend the data, or 1 to append the data. * * Returns: 0 on success * negative number if there are errors */ -int -vector_append(vector_t vector, void *data, ssize_t len) +#define INSERT_PREPEND 0 +#define INSERT_APPEND 1 + +static int +vector_insert(vector_t vector, void *data, ssize_t len, int pos) { struct vectorentry_s *entry; - if (!vector || !data || len <= 0) + if (!vector || !data || len <= 0 || + (pos != INSERT_PREPEND && pos != INSERT_APPEND)) return -EINVAL; entry = safemalloc(sizeof(struct vectorentry_s)); @@ -127,21 +132,42 @@ vector_append(vector_t vector, void *data, ssize_t len) entry->len = len; entry->next = NULL; - if (vector->tail) { - /* If "tail" is not NULL, it points to the last entry */ + /* If there is no head or tail, create them */ + if (!vector->head && !vector->tail) + vector->head = vector->tail = entry; + else if (pos == 0) { + /* prepend the entry */ + entry->next = vector->head; + vector->head = entry; + } else { + /* append the entry */ vector->tail->next = entry; vector->tail = entry; - } else { - /* No "tail", meaning no entries. Create both. */ - vector->head = vector->tail = entry; } - + vector->num_entries++; return 0; } /* + * The following two function are used to make the API clearer. As you + * can see they simply call the vector_insert() function with appropriate + * arguments. + */ +int +vector_append(vector_t vector, void *data, ssize_t len) +{ + return vector_insert(vector, data, len, INSERT_APPEND); +} + +int +vector_prepend(vector_t vector, void *data, ssize_t len) +{ + return vector_insert(vector, data, len, INSERT_PREPEND); +} + +/* * A pointer to the data at position "pos" (zero based) is returned in the * "data" pointer. If the vector is out of bound, data is set to NULL. * diff --git a/src/vector.h b/src/vector.h index 8b938f1..1600ce8 100644 --- a/src/vector.h +++ b/src/vector.h @@ -1,4 +1,4 @@ -/* $Id: vector.h,v 1.2 2003-05-29 20:47:51 rjkaes Exp $ +/* $Id: vector.h,v 1.3 2003-05-29 21:07:22 rjkaes Exp $ * * A vector implementation. The vector can be of an arbritrary length, and * the data for each entry is an lump of data (the size is stored in the @@ -44,15 +44,15 @@ extern vector_t vector_create(void); extern int vector_delete(vector_t vector); /* - * Append an entry to the end of the vector. When you insert a piece of - * data into the vector, the data will be duplicated, so you must free your - * copy if it was created on the heap. The data must be non-NULL and the - * length must be greater than zero. + * When you insert a piece of data into the vector, the data will be + * duplicated, so you must free your copy if it was created on the heap. + * The data must be non-NULL and the length must be greater than zero. * * Returns: negative on error * 0 upon successful insert. */ extern int vector_append(vector_t vector, void *data, ssize_t len); +extern int vector_prepend(vector_t vector, void *data, ssize_t len); /* * A pointer to the data at position "pos" (zero based) is returned in the |