Merge branch 'dev-lib'

[libucw.git] / ucw / fb-atomic.c

diff --git a/ucw/fb-atomic.c b/ucw/fb-atomic.c
index bc350f636944a1486d09875060fe26800e128e13..32c9ca9bfe3facd3da41bc29537bd2f321fd9916 100644 (file)
--- a/ucw/fb-atomic.c
+++ b/ucw/fb-atomic.c
@@ -7,41 +7,34 @@
  *     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;
@@ -79,7 +72,7 @@ fbatomic_spout(struct fastbuf *f)
       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;
@@ -145,6 +138,9 @@ int main(int argc UNUSED, char **argv UNUSED)
 {
   struct fastbuf *f, *g;
 
+  // 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++)