[PATCH] blktrace: cleanup the leftover subbuf code

diff --git a/blktrace.c b/blktrace.c
index 0207dec0e47340bf9fef25a0d6901976db81acfd..a587fec1e81900382141f9a832b00d552a141763 100644 (file)
--- a/blktrace.c
+++ b/blktrace.c
@@ -159,9 +159,8 @@ struct thread_information {
 
        pthread_mutex_t lock;
        struct list_head subbuf_list;
-       void *leftover_ts;
-       int leftover_ts_len;
-       int leftover_ts_max;
+       struct tip_subbuf *leftover_ts;
+       unsigned int leftover_ts_offset;
 };
 
 struct device_information {
@@ -441,16 +440,25 @@ static int flush_subbuf(struct thread_information *tip, struct tip_subbuf *ts)
        int pdu_len, events = 0;
 
        /*
-        * surplus from last run, a little ugly...
+        * surplus from last run
         */
-       if (tip->leftover_ts_len) {
-               if (ts->len + tip->leftover_ts_len > ts->max_len)
-                       ts->buf = realloc(ts->buf, ts->len + tip->leftover_ts_len);
+       if (tip->leftover_ts) {
+               struct tip_subbuf *prev_ts = tip->leftover_ts;
 
-               memmove(ts->buf + tip->leftover_ts_len, ts->buf, ts->len);
-               memcpy(ts->buf, tip->leftover_ts, tip->leftover_ts_len);
-               ts->len += tip->leftover_ts_len;
-               tip->leftover_ts_len = 0;
+               offset = tip->leftover_ts_offset;
+               if (offset + prev_ts->len + ts->len > prev_ts->max_len) {
+                       prev_ts->max_len += ts->len;
+                       prev_ts->buf = realloc(prev_ts->buf, prev_ts->max_len);
+               }
+
+               memcpy(prev_ts->buf + offset + ts->len, ts->buf, ts->len);
+               prev_ts->len += ts->len;
+
+               free(ts->buf);
+               free(ts);
+
+               ts = prev_ts;
+               tip->leftover_ts = NULL;
        }
 
        while (offset + sizeof(*t) <= ts->len) {
@@ -478,20 +486,13 @@ static int flush_subbuf(struct thread_information *tip, struct tip_subbuf *ts)
         * leftover bytes, save them for next time
         */
        if (offset != ts->len) {
-               int surplus = ts->len - offset;
-
-               t = ts->buf + offset;
-               if (surplus > tip->leftover_ts_max) {
-                       tip->leftover_ts = realloc(tip->leftover_ts, surplus);
-                       tip->leftover_ts_max = surplus;
-               }
-
-               memcpy(tip->leftover_ts, ts->buf + offset, surplus);
-               tip->leftover_ts_len = surplus;
+               tip->leftover_ts = ts;
+               tip->leftover_ts_offset = offset;
+       } else {
+               free(ts->buf);
+               free(ts);
        }
 
-       free(ts->buf);
-       free(ts);
        return events;
 }
 
@@ -566,9 +567,8 @@ static int start_threads(struct device_information *dip)
                tip->device = dip;
                tip->events_processed = 0;
                INIT_LIST_HEAD(&tip->subbuf_list);
-               tip->leftover_ts_len = 0;
-               tip->leftover_ts_max = 0;
                tip->leftover_ts = NULL;
+               tip->leftover_ts_offset = 0;
 
                if (pipeline) {
                        tip->ofile = fdopen(STDOUT_FILENO, "w");