From 349c75c16a3713ee6f3ffd701f1c88ce31ecd8de Mon Sep 17 00:00:00 2001 From: Tucker Evans Date: Thu, 11 Jun 2020 14:42:06 -0400 Subject: Add reserve function for double ended queue. --- collections/double_ended_queue.c | 36 +++++++++++++++++++++++++++++++++++- 1 file changed, 35 insertions(+), 1 deletion(-) (limited to 'collections/double_ended_queue.c') diff --git a/collections/double_ended_queue.c b/collections/double_ended_queue.c index 4de6a27..015b90b 100644 --- a/collections/double_ended_queue.c +++ b/collections/double_ended_queue.c @@ -88,7 +88,7 @@ deq *root; int size; tmp = malloc(root->limit * 2 * sizeof(void*)); - assert(root->base); + assert(tmp); if (root->beg <= root->end) { tmp = memcpy(tmp, root->base + root->beg, @@ -405,3 +405,37 @@ deq *root; return root->base[(root->end - 1) % root->limit]; } + +void deq_reserve(root, size) +deq *root; +int size; +{ + void **tmp; + int i, cur_size; + + cur_size = deq_size(root); + for (i = root->limit; i - cur_size < size; i*=2); + + tmp = malloc(i * sizeof(void*)); + assert(tmp); + + if (root->beg <= root->end) { + tmp = memcpy(tmp, root->base + root->beg, + deq_size(root) * sizeof(void*)); + } else { + /*copy beg<->limit*/ + size = root->limit - root->beg; + tmp = memcpy(tmp, root->base + root->beg, size * sizeof(void*)); + assert(tmp); + + /*copy base<->end*/ + tmp = memcpy(tmp + size, root->base, + root->end * sizeof(void*)); + assert(tmp); + } + + root->limit *= 2; + + free(root->base); + root->base = tmp; +} -- cgit v1.1