+/*
+ * Copyright (C) 2009 Andre Noll <maan@systemlinux.org>
+ *
+ * Licensed under the GPL v2. For licencing details see COPYING.
+ */
+
+/** \file prebuffer_filter.c Paraslash's prebuffering filter. */
+
+#include "para.h"
+#include "prebuffer_filter.cmdline.h"
+#include "list.h"
+#include "sched.h"
+#include "ggo.h"
+#include "filter.h"
+#include "string.h"
+#include "error.h"
+
+/** Data specific to the prebuffer filter. */
+struct private_prebuffer_data {
+ /** The configuration data for this instance of the filter. */
+ struct prebuffer_filter_args_info *conf;
+ /** Number of bytes prebuffered or -1 if no longer prebuffering. */
+ int prebuffered;
+ /** End of prebuffering period. */
+ struct timeval barrier;
+};
+
+static ssize_t prebuffer_convert(char *inbuf, size_t inbuf_len,
+ struct filter_node *fn)
+{
+ struct private_prebuffer_data *ppd = fn->private_data;
+ struct prebuffer_filter_args_info *conf = ppd->conf;
+
+ if (inbuf_len == 0) {
+ if (*fn->fc->input_error < 0 && ppd->prebuffered >= 0)
+ goto prebuffer_end;
+ return 0;
+ }
+ if (ppd->prebuffered < 0) {
+ size_t copy = PARA_MIN(inbuf_len, fn->bufsize - fn->loaded);
+ memcpy(fn->buf + fn->loaded, inbuf, copy);
+ fn->loaded += copy;
+ return copy;
+ }
+ if (ppd->prebuffered + inbuf_len > fn->bufsize) {
+ fn->bufsize = PARA_MAX(2 * fn->bufsize,
+ ppd->prebuffered + inbuf_len);
+ fn->buf = para_realloc(fn->buf, fn->bufsize);
+ }
+ memcpy(fn->buf + ppd->prebuffered, inbuf, inbuf_len);
+ if (ppd->prebuffered == 0) {
+ struct timeval tv;
+ PARA_INFO_LOG("prebuffer period %dms\n",
+ conf->duration_arg);
+ ms2tv(conf->duration_arg, &tv);
+ tv_add(&tv, now, &ppd->barrier);
+ }
+ ppd->prebuffered += inbuf_len;
+ PARA_DEBUG_LOG("%zu bytes prebuffered\n", ppd->prebuffered);
+ if (*fn->fc->input_error >= 0) {
+ struct timeval diff;
+ if (tv_diff(now, &ppd->barrier, &diff) < 0)
+ goto out;
+ if (ppd->prebuffered < conf->size_arg)
+ goto out;
+ }
+prebuffer_end:
+ fn->loaded = ppd->prebuffered;
+ ppd->prebuffered = -1;
+out:
+ return inbuf_len;
+}
+
+static void prebuffer_close(struct filter_node *fn)
+{
+ free(fn->private_data);
+ free(fn->buf);
+}
+
+static int prebuffer_parse_config(int argc, char **argv, void **config)
+{
+ struct prebuffer_filter_args_info *prebuffer_conf
+ = para_calloc(sizeof(*prebuffer_conf));
+ int ret = -E_PREBUFFER_SYNTAX;
+
+ if (prebuffer_cmdline_parser(argc, argv, prebuffer_conf))
+ goto err;
+ ret = -ERRNO_TO_PARA_ERROR(EINVAL);
+ if (prebuffer_conf->duration_arg < 0)
+ goto err;
+ if (prebuffer_conf->size_arg < 0)
+ goto err;
+ PARA_NOTICE_LOG("prebuffering %ims, %i bytes\n",
+ prebuffer_conf->duration_arg, prebuffer_conf->size_arg);
+ *config = prebuffer_conf;
+ return 1;
+err:
+ free(prebuffer_conf);
+ return ret;
+}
+
+static void prebuffer_open(struct filter_node *fn)
+{
+ struct private_prebuffer_data *ppd = para_calloc(sizeof(*ppd));
+
+ ppd->conf = fn->conf;
+ fn->private_data = ppd;
+ fn->bufsize = 8192; /* gets increased on demand */
+ fn->buf = para_malloc(fn->bufsize);
+}
+
+/**
+ * The init function of the prebuffer filter.
+ *
+ * \param f Pointer to the struct to initialize.
+ */
+void prebuffer_filter_init(struct filter *f)
+{
+ struct prebuffer_filter_args_info dummy;
+
+ prebuffer_cmdline_parser_init(&dummy);
+ f->open = prebuffer_open;
+ f->close = prebuffer_close;
+ f->convert = prebuffer_convert;
+ f->parse_config = prebuffer_parse_config;
+ f->help = (struct ggo_help) {
+ .short_help = prebuffer_filter_args_info_help,
+ .detailed_help = prebuffer_filter_args_info_detailed_help
+ };
+}