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Diffstat (limited to 'buckets/apr_buckets_pool.c')
| -rw-r--r-- | buckets/apr_buckets_pool.c | 142 |
1 files changed, 142 insertions, 0 deletions
diff --git a/buckets/apr_buckets_pool.c b/buckets/apr_buckets_pool.c new file mode 100644 index 0000000..56ba585 --- /dev/null +++ b/buckets/apr_buckets_pool.c @@ -0,0 +1,142 @@ +/* Licensed to the Apache Software Foundation (ASF) under one or more + * contributor license agreements. See the NOTICE file distributed with + * this work for additional information regarding copyright ownership. + * The ASF licenses this file to You under the Apache License, Version 2.0 + * (the "License"); you may not use this file except in compliance with + * the License. You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +#include "apr_buckets.h" +#define APR_WANT_MEMFUNC +#include "apr_want.h" + +static apr_status_t pool_bucket_cleanup(void *data) +{ + apr_bucket_pool *p = data; + + /* + * If the pool gets cleaned up, we have to copy the data out + * of the pool and onto the heap. But the apr_buckets out there + * that point to this pool bucket need to be notified such that + * they can morph themselves into a regular heap bucket the next + * time they try to read. To avoid having to manipulate + * reference counts and b->data pointers, the apr_bucket_pool + * actually _contains_ an apr_bucket_heap as its first element, + * so the two share their apr_bucket_refcount member, and you + * can typecast a pool bucket struct to make it look like a + * regular old heap bucket struct. + */ + p->heap.base = apr_bucket_alloc(p->heap.alloc_len, p->list); + memcpy(p->heap.base, p->base, p->heap.alloc_len); + p->base = NULL; + p->pool = NULL; + + return APR_SUCCESS; +} + +static apr_status_t pool_bucket_read(apr_bucket *b, const char **str, + apr_size_t *len, apr_read_type_e block) +{ + apr_bucket_pool *p = b->data; + const char *base = p->base; + + if (p->pool == NULL) { + /* + * pool has been cleaned up... masquerade as a heap bucket from now + * on. subsequent bucket operations will use the heap bucket code. + */ + b->type = &apr_bucket_type_heap; + base = p->heap.base; + } + *str = base + b->start; + *len = b->length; + return APR_SUCCESS; +} + +static void pool_bucket_destroy(void *data) +{ + apr_bucket_pool *p = data; + + /* If the pool is cleaned up before the last reference goes + * away, the data is really now on the heap; heap_destroy() takes + * over. free() in heap_destroy() thinks it's freeing + * an apr_bucket_heap, when in reality it's freeing the whole + * apr_bucket_pool for us. + */ + if (p->pool) { + /* the shared resource is still in the pool + * because the pool has not been cleaned up yet + */ + if (apr_bucket_shared_destroy(p)) { + apr_pool_cleanup_kill(p->pool, p, pool_bucket_cleanup); + apr_bucket_free(p); + } + } + else { + /* the shared resource is no longer in the pool, it's + * on the heap, but this reference still thinks it's a pool + * bucket. we should just go ahead and pass control to + * heap_destroy() for it since it doesn't know any better. + */ + apr_bucket_type_heap.destroy(p); + } +} + +APU_DECLARE(apr_bucket *) apr_bucket_pool_make(apr_bucket *b, + const char *buf, apr_size_t length, apr_pool_t *pool) +{ + apr_bucket_pool *p; + + p = apr_bucket_alloc(sizeof(*p), b->list); + + /* XXX: we lose the const qualifier here which indicates + * there's something screwy with the API... + */ + /* XXX: why is this? buf is const, p->base is const... what's + * the problem? --jcw */ + p->base = (char *) buf; + p->pool = pool; + p->list = b->list; + + b = apr_bucket_shared_make(b, p, 0, length); + b->type = &apr_bucket_type_pool; + + /* pre-initialize heap bucket member */ + p->heap.alloc_len = length; + p->heap.base = NULL; + p->heap.free_func = apr_bucket_free; + + apr_pool_cleanup_register(p->pool, p, pool_bucket_cleanup, + apr_pool_cleanup_null); + return b; +} + +APU_DECLARE(apr_bucket *) apr_bucket_pool_create(const char *buf, + apr_size_t length, + apr_pool_t *pool, + apr_bucket_alloc_t *list) +{ + apr_bucket *b = apr_bucket_alloc(sizeof(*b), list); + + APR_BUCKET_INIT(b); + b->free = apr_bucket_free; + b->list = list; + return apr_bucket_pool_make(b, buf, length, pool); +} + +APU_DECLARE_DATA const apr_bucket_type_t apr_bucket_type_pool = { + "POOL", 5, APR_BUCKET_DATA, + pool_bucket_destroy, + pool_bucket_read, + apr_bucket_setaside_noop, /* don't need to setaside thanks to the cleanup*/ + apr_bucket_shared_split, + apr_bucket_shared_copy +}; |