expose bufferevent_setwatermark via header files and fix high watermark on read

svn:r729

diff --git a/ChangeLog b/ChangeLog
index 6dd51b6615c96108453094edc7d1ad2c1cf23850..edc102612cbe6bd66e60f995b897b437a482130c 100644 (file)
--- a/ChangeLog
+++ b/ChangeLog
@@ -71,6 +71,7 @@ Changes in current version:
  o Rename internal memory management functions.
  o New functions (event_assign, event_new, event_free) for use by apps that want to be safely threadsafe, or want to remain ignorant of the contents of struct event.
  o introduce bufferevent_read_buffer; allows reading without memory copy.
+ o expose bufferevent_setwatermark via header files and fix high watermark on read
 
 Changes in 1.4.0:
  o allow \r or \n individually to separate HTTP headers instead of the standard "\r\n"; from Charles Kerr.

diff --git a/evbuffer.c b/evbuffer.c
index bb719b3cd408d49790ec4d3afddec9e59650d26a..51ee6c0637e52436482ef2437d383ca90cfdc0d2 100644 (file)
--- a/evbuffer.c
+++ b/evbuffer.c
@@ -56,7 +56,6 @@
 
 /* prototypes */
 
-void bufferevent_setwatermark(struct bufferevent *, short, size_t, size_t);
 void bufferevent_read_pressure_cb(struct evbuffer *, size_t, size_t, void *);
 
 static int
@@ -112,8 +111,17 @@ bufferevent_readcb(evutil_socket_t fd, short event, void *arg)
         * If we have a high watermark configured then we don't want to
         * read more data than would make us reach the watermark.
         */
-       if (bufev->wm_read.high != 0)
-               howmuch = bufev->wm_read.high;
+       if (bufev->wm_read.high != 0) {
+               howmuch = bufev->wm_read.high - EVBUFFER_LENGTH(bufev->input);
+               /* we might have lowered the watermark, stop reading */
+               if (howmuch <= 0) {
+                       struct evbuffer *buf = bufev->input;
+                       event_del(&bufev->ev_read);
+                       evbuffer_setcb(buf,
+                           bufferevent_read_pressure_cb, bufev);
+                       return;
+               }
+       }
 
        res = evbuffer_read(bufev->input, fd, howmuch);
        if (res == -1) {
@@ -135,7 +143,7 @@ bufferevent_readcb(evutil_socket_t fd, short event, void *arg)
        len = EVBUFFER_LENGTH(bufev->input);
        if (bufev->wm_read.low != 0 && len < bufev->wm_read.low)
                return;
-       if (bufev->wm_read.high != 0 && len > bufev->wm_read.high) {
+       if (bufev->wm_read.high != 0 && len >= bufev->wm_read.high) {
                struct evbuffer *buf = bufev->input;
                event_del(&bufev->ev_read);
 

diff --git a/include/event2/bufferevent.h b/include/event2/bufferevent.h
index 7ef7e17d19196997c378287133464c48d8ede1dc..2377ca354a46b3f6794303749bf296524851bc5a 100644 (file)
--- a/include/event2/bufferevent.h
+++ b/include/event2/bufferevent.h
@@ -223,6 +223,24 @@ int bufferevent_disable(struct bufferevent *bufev, short event);
 void bufferevent_settimeout(struct bufferevent *bufev,
     int timeout_read, int timeout_write);
 
+/**
+  Sets the watermarks for read and write events.
+
+  On input, a bufferevent does not invoke the user read callback unless
+  there is at least low watermark data in the buffer.   If the read buffer
+  is beyond the high watermark, the buffevent stops reading from the network.
+
+  On output, the user write callback is invoked whenever the buffered data
+  falls below the low watermark.
+
+  @param bufev the bufferevent to be modified
+  @param events EV_READ, EV_WRITE or both
+  @param lowmark the lower watermark to set
+  @param highmark the high watermark to set
+*/
+
+void bufferevent_setwatermark(struct bufferevent *bufev, short events,
+    size_t lowmark, size_t highmark);
 
 #define EVBUFFER_INPUT(x)      (x)->input
 #define EVBUFFER_OUTPUT(x)     (x)->output