generic_filter_pre_select(): Fix off-by-one.

[paraslash.git] / filter_common.c

diff --git a/filter_common.c b/filter_common.c
index 7c71ff39243a7a63f7026c11726418377790c87e..a27c2d303ad28d823ae9af20eeb4878f9300cad1 100644 (file)
--- a/filter_common.c
+++ b/filter_common.c
@@ -9,12 +9,14 @@
 #include <regex.h>
 #include <sys/types.h>
 #include <dirent.h>
+#include <stdbool.h>
 
 #include "para.h"
 #include "list.h"
 #include "sched.h"
 #include "fd.h"
 #include "ggo.h"
+#include "buffer_tree.h"
 #include "filter.h"
 #include "error.h"
 #include "string.h"
@@ -273,3 +275,39 @@ void print_filter_helps(int detailed)
        }
 
 }
+
+/** 640K ought to be enough for everybody ;) */
+#define FILTER_MAX_PENDING (640 * 1024)
+
+int prepare_filter_node(struct filter_node *fn)
+{
+       struct btr_node *btrn = fn->btrn;
+       size_t iqs;
+
+       if (btr_eof(btrn))
+               return -E_FC_EOF;
+       if (btr_bytes_pending(btrn) > FILTER_MAX_PENDING)
+               return 0;
+       iqs = btr_get_input_queue_size(btrn);
+       if (iqs < fn->min_iqs && !btr_no_parent(btrn))
+               return 0;
+       assert(iqs != 0);
+       /* avoid "buffer too small" errors from the decoder */
+       btr_merge(btrn, fn->min_iqs);
+       return 1;
+}
+
+void generic_filter_pre_select(struct sched *s, struct task *t)
+{
+       struct filter_node *fn = container_of(t, struct filter_node, task);
+       size_t iqs = btr_get_input_queue_size(fn->btrn);
+
+       t->error = 0;
+       if (iqs < fn->min_iqs)
+               return;
+       if (btr_bytes_pending(fn->btrn) > FILTER_MAX_PENDING)
+               return; /* FIXME, should use reasonable bound on timeout */
+       s->timeout.tv_sec = 0;
+       s->timeout.tv_usec = 1;
+}
+