* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
- *
- * $Id$
*/
+/** @file
+ * @brief Implementation of functions dealing with data buffers.
+ * @version $Id$
+ */
+#include "config.h"
+
#include "dbuf.h"
#include "ircd_alloc.h"
#include "ircd_chattr.h"
+#include "ircd_features.h"
+#include "ircd_log.h"
#include "send.h"
#include "sys.h" /* MIN */
-#include <assert.h>
+/* #include <assert.h> -- Now using assert in ircd_log.h */
#include <string.h>
/*
* this package maintaining the buffer on disk, either]
*/
+/** Number of dbufs allocated.
+ * This should only be modified by dbuf.c.
+ */
int DBufAllocCount = 0;
+/** Number of dbufs in use.
+ * This should only be modified by dbuf.c.
+ */
int DBufUsedCount = 0;
+/** List of allocated but unused DBuf structures. */
static struct DBufBuffer *dbufFreeList = 0;
+/** Size of data for a single DBufBuffer. */
#define DBUF_SIZE 2048
+/** Single data buffer in a DBuf. */
struct DBufBuffer {
- struct DBufBuffer *next; /* Next data buffer, NULL if last */
- char *start; /* data starts here */
- char *end; /* data ends here */
- char data[DBUF_SIZE]; /* Actual data stored here */
+ struct DBufBuffer *next; /**< Next data buffer, NULL if last */
+ char *start; /**< data starts here */
+ char *end; /**< data ends here */
+ char data[DBUF_SIZE]; /**< Actual data stored here */
};
+/** Return memory used by allocated data buffers.
+ * @param[out] allocated Receives number of bytes allocated to DBufs.
+ * @param[out] used Receives number of bytes for currently used DBufs.
+ */
void dbuf_count_memory(size_t *allocated, size_t *used)
{
assert(0 != allocated);
*used = DBufUsedCount * sizeof(struct DBufBuffer);
}
-/*
- * dbuf_alloc - allocates a DBufBuffer structure from the free list or
- * creates a new one.
+/** Allocate a new DBufBuffer.
+ * If #dbufFreeList != NULL, use the head of that list; otherwise,
+ * allocate a new buffer.
+ * @return Newly allocated buffer list.
*/
static struct DBufBuffer *dbuf_alloc(void)
{
dbufFreeList = db->next;
++DBufUsedCount;
}
- else if (DBufAllocCount * DBUF_SIZE < BUFFERPOOL) {
+ else if (DBufAllocCount * DBUF_SIZE < feature_int(FEAT_BUFFERPOOL)) {
db = (struct DBufBuffer*) MyMalloc(sizeof(struct DBufBuffer));
assert(0 != db);
++DBufAllocCount;
return db;
}
-/*
- * dbuf_free - return a struct DBufBuffer structure to the freelist
+/** Release a DBufBuffer back to the free list.
+ * @param[in] db Data buffer to release.
*/
static void dbuf_free(struct DBufBuffer *db)
{
dbufFreeList = db;
}
-/*
- * This is called when malloc fails. Scrap the whole content
- * of dynamic buffer. (malloc errors are FATAL, there is no
- * reason to continue this buffer...).
- * After this the "dbuf" has consistent EMPTY status.
+/** Handle a memory allocation error on a DBuf.
+ * This frees all the buffers owned by the DBuf, since we have to
+ * close the associated connection.
+ * @param[in] dyn DBuf to clean out.
+ * @return Zero.
*/
static int dbuf_malloc_error(struct DBuf *dyn)
{
return 0;
}
-/*
- * dbuf_put - Append the number of bytes to the buffer, allocating memory
- * as needed. Bytes are copied into internal buffers from users buffer.
- *
- * Returns > 0, if operation successful
- * < 0, if failed (due memory allocation problem)
- *
- * dyn: Dynamic buffer header
- * buf: Pointer to data to be stored
- * length: Number of bytes to store
+/** Append bytes to a data buffer.
+ * @param[in] dyn Buffer to append to.
+ * @param[in] buf Data to append.
+ * @param[in] length Number of bytes to append.
+ * @return Non-zero on success, or zero on failure.
*/
int dbuf_put(struct DBuf *dyn, const char *buf, unsigned int length)
{
for (; length > 0; h = &(db->next)) {
if (0 == (db = *h)) {
if (0 == (db = dbuf_alloc())) {
-#if defined(HAS_FERGUSON_FLUSHER)
- /*
- * from "Married With Children" episode were Al bought a REAL toilet
- * on the black market because he was tired of the wimpy water
- * conserving toilets they make these days --Bleep
- */
- /*
- * Apparently this doesn't work, the server _has_ to
- * dump a few clients to handle the load. A fully loaded
- * server cannot handle a net break without dumping some
- * clients. If we flush the connections here under a full
- * load we may end up starving the kernel for mbufs and
- * crash the machine
- */
- /*
- * attempt to recover from buffer starvation before
- * bailing this may help servers running out of memory
- */
- flush_sendq_except(dyn);
- if (0 == (db = dbuf_alloc()))
-#endif
+ if (feature_bool(FEAT_HAS_FERGUSON_FLUSHER)) {
+ /*
+ * from "Married With Children" episode were Al bought a REAL toilet
+ * on the black market because he was tired of the wimpy water
+ * conserving toilets they make these days --Bleep
+ */
+ /*
+ * Apparently this doesn't work, the server _has_ to
+ * dump a few clients to handle the load. A fully loaded
+ * server cannot handle a net break without dumping some
+ * clients. If we flush the connections here under a full
+ * load we may end up starving the kernel for mbufs and
+ * crash the machine
+ */
+ /*
+ * attempt to recover from buffer starvation before
+ * bailing this may help servers running out of memory
+ */
+ flush_connections(0);
+ db = dbuf_alloc();
+ }
+
+ if (0 == db)
return dbuf_malloc_error(dyn);
}
dyn->tail = db;
return 1;
}
-/*
- * dbuf_map, dbuf_delete
- *
- * These functions are meant to be used in pairs and offer a more efficient
- * way of emptying the buffer than the normal 'dbuf_get' would allow--less
- * copying needed.
- *
- * map returns a pointer to a largest contiguous section
- * of bytes in front of the buffer, the length of the
- * section is placed into the indicated "long int"
- * variable. Returns NULL *and* zero length, if the
- * buffer is empty.
- *
- * delete removes the specified number of bytes from the
- * front of the buffer releasing any memory used for them.
- *
- * Example use (ignoring empty condition here ;)
- *
- * buf = dbuf_map(&dyn, &count);
- * <process N bytes (N <= count) of data pointed by 'buf'>
- * dbuf_delete(&dyn, N);
- *
- * Note: delete can be used alone, there is no real binding
- * between map and delete functions...
- *
- * dyn: Dynamic buffer header
- * length: Return number of bytes accessible
+/** Get the first contiguous block of data from a DBuf.
+ * Generally a call to dbuf_map(dyn, &count) will be followed with a
+ * call to dbuf_delete(dyn, count).
+ * @param[in] dyn DBuf to retrieve data from.
+ * @param[out] length Receives number of bytes in block.
+ * @return Pointer to start of block (or NULL if the first block is empty).
*/
const char *dbuf_map(const struct DBuf* dyn, unsigned int* length)
{
return dyn->head->start;
}
-/*
- * dbuf_delete - delete length bytes from DBuf
- *
- * dyn: Dynamic buffer header
- * length: Number of bytes to delete
+/** Discard data from a DBuf.
+ * @param[in,out] dyn DBuf to drop data from.
+ * @param[in] length Number of bytes to discard.
*/
void dbuf_delete(struct DBuf *dyn, unsigned int length)
{
}
}
-/*
- * dbuf_get
- *
- * Remove number of bytes from the buffer, releasing dynamic memory,
- * if applicaple. Bytes are copied from internal buffers to users buffer.
- *
- * Returns the number of bytes actually copied to users buffer,
- * if >= 0, any value less than the size of the users
- * buffer indicates the dbuf became empty by this operation.
- *
- * Return 0 indicates that buffer was already empty.
- *
- * dyn: Dynamic buffer header
- * buf: Pointer to buffer to receive the data
- * length: Max amount of bytes that can be received
+/** Copy data from a buffer and remove what was copied.
+ * @param[in,out] dyn Buffer to copy from.
+ * @param[out] buf Buffer to write to.
+ * @param[in] length Maximum number of bytes to copy.
+ * @return Number of bytes actually copied.
*/
unsigned int dbuf_get(struct DBuf *dyn, char *buf, unsigned int length)
{
return moved;
}
+/** Flush empty lines from a buffer.
+ * @param[in,out] dyn Data buffer to flush.
+ * @return Number of bytes in first available block (or zero if none).
+ */
static unsigned int dbuf_flush(struct DBuf *dyn)
{
struct DBufBuffer *db = dyn->head;
return dyn->length;
}
-
-/*
- * dbuf_getmsg - Check the buffers to see if there is a string which is
- * terminated with either a \r or \n present. If so, copy as much as
- * possible (determined by length) into buf and return the amount copied
- * else return 0.
+/** Copy a single line from a data buffer.
+ * If the output buffer cannot hold the whole line, or if there is no
+ * EOL in the buffer, return 0.
+ * @param[in,out] dyn Data buffer to copy from.
+ * @param[out] buf Buffer to copy to.
+ * @param[in] length Maximum number of bytes to copy.
+ * @return Number of bytes copied to \a buf.
*/
unsigned int dbuf_getmsg(struct DBuf *dyn, char *buf, unsigned int length)
{
projects / ircu2.10.12-pk.git / blobdiff