* of the GNU Lesser General Public License.
*/
-/*
- * This fastbuf backend is intended for cases where several threads
- * of a single program append records to a single file and while the
- * record can mix in an arbitrary way, the bytes inside a single
- * record must remain uninterrupted.
- *
- * In case of files with fixed record size, we just allocate the
- * buffer to hold a whole number of records and take advantage
- * of the atomicity of the write() system call.
- *
- * With variable-sized records, we need another solution: when
- * writing a record, we keep the fastbuf in a locked state, which
- * prevents buffer flushing (and if the buffer becomes full, we extend it),
- * and we wait for an explicit commit operation which write()s the buffer
- * if the free space in the buffer falls below the expected maximum record
- * length.
- *
- * fbatomic_open() is called with the following parameters:
- * name - name of the file to open
- * master - fbatomic for the master thread or NULL if it's the first open
- * bufsize - initial buffer size
- * record_len - record length for fixed-size records;
- * or -(expected maximum record length) for variable-sized ones.
- */
-
-#define LOCAL_DEBUG
-
#include "ucw/lib.h"
#include "ucw/fastbuf.h"
#include "ucw/lfs.h"
+#include "ucw/conf.h"
#include <string.h>
#include <fcntl.h>
#include <unistd.h>
+static uns trace;
+
+#ifndef TEST
+
+static struct cf_section fbatomic_config = {
+ CF_ITEMS {
+ CF_UNS("Trace", &trace)
+ }
+};
+
+static void CONSTRUCTOR fbatomic_init_config(void)
+{
+ cf_declare_section("FBAtomic", &fbatomic_config, 1);
+}
+
+#endif
+
+#define TRACE(m...) do { if(trace) msg(L_DEBUG, "FB_ATOMIC: " m); } while(0)
+
struct fb_atomic_file {
int fd;
int use_count;
uns written = f->bptr - f->buffer;
uns size = f->bufend - f->buffer + F->slack_size;
F->slack_size *= 2;
- DBG("Reallocating buffer for atomic file %s with slack %d", f->name, F->slack_size);
+ TRACE("Reallocating buffer for atomic file %s with slack %d", f->name, F->slack_size);
f->buffer = xrealloc(f->buffer, size);
f->bufend = f->buffer + size;
f->bptr = f->buffer + written;
{
struct fastbuf *f, *g;
- log(L_INFO, "Testing block writes");
+ // Always trace in the test
+ trace = 1;
+
+ msg(L_INFO, "Testing block writes");
f = fbatomic_open("test", NULL, 16, 4);
for (u32 i=0; i<17; i++)
bwrite(f, &i, 4);
bclose(f);
- log(L_INFO, "Testing interleaved var-size writes");
+ msg(L_INFO, "Testing interleaved var-size writes");
f = fbatomic_open("test2", NULL, 23, -5);
g = fbatomic_open("test2", f, 23, -5);
for (int i=0; i<100; i++)