From 87c0882e7f881047a4a6fae0875f481cd490cac4 Mon Sep 17 00:00:00 2001
From: nico <nico@9862a28c-4e93-4879-ac26-10afcf840a8f>
Date: Thu, 19 Jul 2007 00:20:41 +0000
Subject: [PATCH] Initial implementation of buffer extending. Debug output
 reduced.

git-svn-id: svn://jdgordon.mine.nu/mob@62 9862a28c-4e93-4879-ac26-10afcf840a8f
---
 testplugin.c | 33 ++++++++++++++++++++++++---------
 1 file changed, 24 insertions(+), 9 deletions(-)

diff --git a/testplugin.c b/testplugin.c
index c954b5e..37b0d58 100644
--- a/testplugin.c
+++ b/testplugin.c
@@ -119,7 +119,6 @@ static struct memory_handle *add_handle(size_t *data_size)
     /* make sure buf_widx is 32-bit aligned so that the handle struct is,
        but before that we check we can actually align. */
     if (RINGBUF_ADD_CROSS(buf_widx, 3, buf_ridx) >= 0) {
-        DEBUGF("no space to even align\n");
         return NULL;
     }
     buf_widx = (RINGBUF_ADD(buf_widx, 3)) & ~3;
@@ -134,7 +133,6 @@ static struct memory_handle *add_handle(size_t *data_size)
         len -= overlap + 1;
     }
     if (len < sizeof(struct memory_handle)) {
-        DEBUGF("no space to add the handle\n");
         return NULL;
     }
 
@@ -333,7 +331,7 @@ static ssize_t buffer_handle(int handle_id)
             break;
 
         /* rc is the actual amount read */
-        int rc = rb->read(h->fd, &buffer[RINGBUF_ADD(h->data, h->widx)], copy_n);
+        int rc = rb->read(h->fd, &buffer[RINGBUF_ADD(h->data,h->widx)], copy_n);
 
         if (rc < 0)
         {
@@ -348,6 +346,24 @@ static ssize_t buffer_handle(int handle_id)
         h->available += rc;
         ret += rc;
         h->filerem -= rc;
+
+        if (h->ridx <= h->widx && h->data_len < h->filerem) {
+            /* Check whether we can extend the buffer to avoid unnecessary
+               wrapping. */
+            size_t extend_by = 0;
+            if (h == cur_handle) {
+                extend_by = RINGBUF_SUB(buf_ridx, buf_widx) - 1;
+            } else {
+                extend_by = RINGBUF_SUB((size_t)((void*)h->next-(void*)buffer),
+                                        RINGBUF_ADD(h->data, h->data_len));
+            }
+
+            h->data_len += extend_by;
+            if (extend_by > 0)
+                DEBUGF("extended the handle data buffer by %ld bytes\n",
+                       extend_by);
+        }
+
     }
 
     if (h->filerem == 0) {
@@ -378,7 +394,7 @@ static void free_buffer(int handle_id)
     DEBUGF("old state: data: %ld, data_len: %ld, avail: %ld, ridx: %ld, widx: %ld\n",
            h->data, h->data_len, h->available, h->ridx, h->widx);
 
-    if (h->widx != 0 && h->ridx > h->widx) {
+    if (h->ridx > h->widx) {
         /* We don't want to overwrite a useful part of the buffer */
         return;
     }
@@ -459,14 +475,14 @@ static size_t used_space(void)
 */
 int bufopen(char *file, size_t offset)
 {
-    DEBUGF("bufopen: %s (offset: %ld)\n", file, offset);
-
     int fd = rb->open(file, O_RDONLY);
     if (fd < 0)
         return -1;
 
     size_t size = rb->filesize(fd) - offset + 1;
-    DEBUGF("we want to allocate %ld bytes\n", size);
+    DEBUGF("bufopen: %s (offset: %ld) (%ld bytes needed)... ",
+           file, offset, size);
+
     struct memory_handle *h = add_handle(&size);
     if (!h)
     {
@@ -474,7 +490,6 @@ int bufopen(char *file, size_t offset)
         rb->close(fd);
         return -1;
     }
-    DEBUGF("allocated %ld bytes\n", size);
 
     if (offset) rb->lseek(fd, offset, SEEK_SET);
     rb->strncpy(h->path, file, MAX_PATH);
@@ -490,7 +505,7 @@ int bufopen(char *file, size_t offset)
 
     buf_widx = RINGBUF_ADD(buf_widx, size);
 
-    DEBUGF("added handle : %d\n", h->id);
+    DEBUGF("allocated %ld bytes. ID: %d\n", size, h->id);
     return h->id;
 }
 
-- 
2.11.4.GIT