RIO: improve comments and fix lines over 80 cols.

1 files changed, 23 insertions, 13 deletions

diff --git a/src/rio.c b/src/rio.c
index 93200b682..fb8985f7c 100644
--- a/src/rio.c
+++ b/src/rio.c
@@ -157,7 +157,11 @@ void rioInitWithFile(rio *r, FILE *fp) {
     r->io.file.autosync = 0;
 }
 
-/* ------------------- File descriptor implementation ------------------- */
+/* --------------------- File descriptor implementation ---------------------
+ * This RIO target is used when reading an RDB file from the network (when
+ * the diskless slave feature is enabled), so it implements a buffered read
+ * target, and does not implement writing.
+ * ------------------------------------------------------------------------ */
 
 static size_t rioFdWrite(rio *r, const void *buf, size_t len) {
     UNUSED(r);
@@ -170,25 +174,25 @@ static size_t rioFdWrite(rio *r, const void *buf, size_t len) {
 static size_t rioFdRead(rio *r, void *buf, size_t len) {
     size_t avail = sdslen(r->io.fd.buf)-r->io.fd.pos;
 
-    /* if the buffer is too small for the entire request: realloc */
+    /* If the buffer is too small for the entire request: realloc */
     if (sdslen(r->io.fd.buf) + sdsavail(r->io.fd.buf) < len)
         r->io.fd.buf = sdsMakeRoomFor(r->io.fd.buf, len - sdslen(r->io.fd.buf));
 
-    /* if the remaining unused buffer is not large enough: memmove so that we can read the rest */
+    /* If the remaining unused buffer is not large enough: memmove so that
+     * we can read the rest */
     if (len > avail && sdsavail(r->io.fd.buf) < len - avail) {
         sdsrange(r->io.fd.buf, r->io.fd.pos, -1);
         r->io.fd.pos = 0;
     }
 
-    /* if we don't already have all the data in the sds, read more */
+    /* If we don't already have all the data in the sds, read more */
     while (len > sdslen(r->io.fd.buf) - r->io.fd.pos) {
         size_t buffered = sdslen(r->io.fd.buf) - r->io.fd.pos;
         size_t toread = len - buffered;
-        /* read either what's missing, or PROTO_IOBUF_LEN, the bigger of the two */
-        if (toread < PROTO_IOBUF_LEN)
-            toread = PROTO_IOBUF_LEN;
-        if (toread > sdsavail(r->io.fd.buf))
-            toread = sdsavail(r->io.fd.buf);
+        /* Read either what's missing, or PROTO_IOBUF_LEN, the bigger of the
+         * two */
+        if (toread < PROTO_IOBUF_LEN) toread = PROTO_IOBUF_LEN;
+        if (toread > sdsavail(r->io.fd.buf)) toread = sdsavail(r->io.fd.buf);
         if (r->io.fd.read_limit != 0 &&
             r->io.fd.read_so_far + buffered + toread > r->io.fd.read_limit) {
             if (r->io.fd.read_limit >= r->io.fd.read_so_far - buffered)
@@ -198,7 +202,8 @@ static size_t rioFdRead(rio *r, void *buf, size_t len) {
                 return 0;
             }
         }
-        int retval = read(r->io.fd.fd, (char*)r->io.fd.buf + sdslen(r->io.fd.buf), toread);
+        int retval = read(r->io.fd.fd,
+                          (char*)r->io.fd.buf + sdslen(r->io.fd.buf), toread);
         if (retval <= 0) {
             if (errno == EWOULDBLOCK) errno = ETIMEDOUT;
             return 0;
@@ -264,7 +269,12 @@ void rioFreeFd(rio *r, sds* out_remainingBufferedData) {
     r->io.fd.buf = NULL;
 }
 
-/* ------------------- File descriptors set implementation ------------------- */
+/* ------------------- File descriptors set implementation ------------------
+ * This RIO target is used for master-side diskless implementation, when we
+ * write our RDB file at the same time to multiple slaves that are waiting
+ * for a full SYNC. Reading from this target is not implemented because is
+ * never used.
+ * ------------------------------------------------------------------------ */
 
 /* Returns 1 or 0 for success/failure.
  * The function returns success as long as we are able to correctly write
@@ -390,7 +400,7 @@ void rioFreeFdset(rio *r) {
     sdsfree(r->io.fdset.buf);
 }
 
-/* ---------------------------- Generic functions ---------------------------- */
+/* ---------------------------- Generic functions --------------------------- */
 
 /* This function can be installed both in memory and file streams when checksum
  * computation is needed. */
@@ -411,7 +421,7 @@ void rioSetAutoSync(rio *r, off_t bytes) {
     r->io.file.autosync = bytes;
 }
 
-/* --------------------------- Higher level interface --------------------------
+/* --------------------------- Higher level interface -------------------------
  *
  * The following higher level functions use lower level rio.c functions to help
  * generating the Redis protocol for the Append Only File. */