Actually commit the header added in r1157354

git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@1157361 13f79535-47bb-0310-9956-ffa450edef68

diff --git a/include/util_varbuf.h b/include/util_varbuf.h
new file mode 100644 (file)
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--- /dev/null
+++ b/include/util_varbuf.h
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+/* 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.
+ */
+
+/**
+ * @file util_varbuf.h
+ * @brief Apache resizable variable length buffer library
+ */
+
+#ifndef AP_VARBUF_H
+#define AP_VARBUF_H
+
+#include "apr.h"
+#include "apr_allocator.h"
+
+#include "httpd.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#define AP_VARBUF_UNKNOWN APR_SIZE_MAX
+struct ap_varbuf_info;
+
+/** A resizable buffer */
+struct ap_varbuf {
+    /** the actual buffer */
+    char *buf;
+
+    /** allocated size of the buffer (minus one for the final \0);
+     *  must only be changed using ap_varbuf_grow() */
+    apr_size_t avail;
+
+    /** length of string in buffer, or AP_VARBUF_UNKNOWN. This determines how
+     *  much memory is copied by ap_varbuf_grow() and where
+     *  ap_varbuf_strmemcat() will append to the buffer. */
+    apr_size_t strlen;
+
+    /** the pool for memory allocations and for registering the cleanup;
+     *  the buffer memory will be released when this pool is destroyed */
+    apr_pool_t *pool;
+
+    /** opaque info for memory allocation */
+    struct ap_varbuf_info *info;
+};
+
+/** initialize a resizable buffer. It is safe to re-initialize a prevously
+ *  used ap_varbuf. The old buffer will be released when the corresponding
+ *  pool is destroyed.
+ * @param pool the pool to allocate small buffers from and to register the
+ *        cleanup with
+ * @param vb pointer to the ap_varbuf struct
+ * @init_size the initial size of the buffer (see ap_varbuf_grow() for details)
+ */
+AP_DECLARE(void) ap_varbuf_init(apr_pool_t *pool, struct ap_varbuf *vb,
+                                apr_size_t init_size);
+
+/** grow a resizable buffer. If the vb->buf cannot be grown in place, it will
+ *  be reallocated and up to vb->strlen + 1 bytes of memory will be copied to
+ *  the new location. If vb->strlen == AP_VARBUF_UNKNOWN, the whole buffer
+ *  is copied.
+ * @param vb pointer to the ap_varbuf struct
+ * @param new_size the minimum new size of the buffer
+ * @note ap_varbuf_grow() will usually at least double vb->buf's size with
+ *       every invocation in order to reduce reallications.
+ * @note ap_varbuf_grow() will use pool memory for small and allocator
+ *       mem nodes for larger allocations.
+ * @note ap_varbuf_grow() will call vb->pool's abort function if out of memory.
+ */
+AP_DECLARE(void) ap_varbuf_grow(struct ap_varbuf *vb, apr_size_t new_size);
+
+/** Release memory from a ap_varbuf immediately, if possible.
+ *  This allows to free large buffers before the corresponding pool is
+ *  destroyed. Only larger allocations using mem nodes will be freed.
+ * @param vb pointer to the ap_varbuf struct
+ * @note After ap_varbuf_free(), vb must not be used unless ap_varbuf_init()
+ *       is called again.
+ */
+AP_DECLARE(void) ap_varbuf_free(struct ap_varbuf *vb);
+
+/** Concatenate a string to an ap_varbuf
+ * @param vb pointer to the ap_varbuf struct
+ * @param str the string to append; must be at least len bytes long
+ * @param len the number of characters of *str to concatenate to the buf
+ * @note vb->strlen will be set to the length of the new string
+ * @note vb->buf will be null-terminated
+ */
+AP_DECLARE(void) ap_varbuf_strmemcat(struct ap_varbuf *vb, const char *str,
+                                     int len);
+
+/** Concatenate a string to an ap_varbuf
+ * @param vb pointer to the ap_varbuf struct
+ * @param str the string to append
+ * @note vb->strlen will be set to the length of the new string
+ */
+#define ap_varbuf_strcat(vb, str) ap_varbuf_strmemcat(vb, str, strlen(str))
+
+/** Read a line from an ap_configfile_t into an ap_varbuf.
+ * @param vb pointer to the ap_varbuf struct
+ * @param cfg pointer to the ap_configfile_t
+ * @param max_len (soft) limit for the size of the buffer
+ * @return see ap_cfg_getline()
+ * @note The buffer will not be grown once it has reached at least max_len
+ *       bytes. This means that the returned line can be longer than max_len.
+ * @note vb->strlen will be set to the length of the line
+ */
+AP_DECLARE(apr_status_t) ap_varbuf_cfg_getline(struct ap_varbuf *vb,
+                                               ap_configfile_t *cfp,
+                                               apr_size_t max_len);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif  /* !AP_VARBUF_H */