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authorMark Purcell <msp@debian.org>2010-02-25 21:13:46 +1100
committeretobi <git@e-tobi.net>2013-09-03 09:48:46 +0200
commit665818f1969f893f05edf5b70eb1804c89b2829e (patch)
tree34ba68cee03c52d769a5a51b456b7e9d63cd091a /util/alevt/cache.c
parent109c7947d6a11a2a54eff1b19615ed80ea2f0602 (diff)
parent9fe4d4ea9c054e539ab679ed2e9c076c35beb69d (diff)
downloadlinux-dvb-apps-665818f1969f893f05edf5b70eb1804c89b2829e.tar.gz
Imported Debian patch 1.1.1+rev1355-1debian/1.1.1+rev1355-1
Diffstat (limited to 'util/alevt/cache.c')
-rw-r--r--util/alevt/cache.c229
1 files changed, 229 insertions, 0 deletions
diff --git a/util/alevt/cache.c b/util/alevt/cache.c
new file mode 100644
index 0000000..c747448
--- /dev/null
+++ b/util/alevt/cache.c
@@ -0,0 +1,229 @@
+#include <stdlib.h>
+#include <string.h>
+#include "misc.h"
+#include "dllist.h"
+#include "cache.h"
+#include "help.h"
+
+
+static inline int hash(int pgno)
+{
+ // very simple...
+ return pgno % HASH_SIZE;
+}
+
+
+static void do_erc(struct vt_page *ovtp, struct vt_page *nvtp)
+{
+ int l, c;
+
+ if (nvtp->errors == 0 && ovtp->lines == nvtp->lines)
+ return;
+
+ for (l = 0; l < H; ++l)
+ {
+ if (~nvtp->lines & (1 << l))
+ memcpy(nvtp->data[l], ovtp->data[l], W);
+ else if (ovtp->lines & (1 << l))
+ for (c = 0; c < W; ++c)
+ if (nvtp->data[l][c] == BAD_CHAR)
+ nvtp->data[l][c] = ovtp->data[l][c];
+ }
+ nvtp->lines |= ovtp->lines;
+}
+
+
+static void cache_close(struct cache *ca)
+{
+ struct cache_page *cp;
+ int i;
+
+ for (i = 0; i < HASH_SIZE; ++i)
+ while (not dl_empty(ca->hash + i))
+ {
+ cp = PTR ca->hash[i].first;
+ dl_remove(cp->node);
+ free(cp);
+ }
+ free(ca);
+}
+
+
+static void cache_reset(struct cache *ca)
+{
+ struct cache_page *cp, *cpn;
+ int i;
+
+ for (i = 0; i < HASH_SIZE; ++i)
+ for (cp = PTR ca->hash[i].first; cpn = PTR cp->node->next; cp = cpn)
+ if (cp->page->pgno / 256 != 9) // don't remove help pages
+ {
+ dl_remove(cp->node);
+ free(cp);
+ ca->npages--;
+ }
+ memset(ca->hi_subno, 0, sizeof(ca->hi_subno[0]) * 0x900);
+}
+
+/* Get a page from the cache.
+ If subno is SUB_ANY, the newest subpage of that page is returned */
+
+
+static struct vt_page * cache_get(struct cache *ca, int pgno, int subno)
+{
+ struct cache_page *cp;
+ int h = hash(pgno);
+
+ for (cp = PTR ca->hash[h].first; cp->node->next; cp = PTR cp->node->next)
+ if (cp->page->pgno == pgno)
+ if (subno == ANY_SUB || cp->page->subno == subno)
+ {
+ // found, move to front (make it 'new')
+ dl_insert_first(ca->hash + h, dl_remove(cp->node));
+ return cp->page;
+ }
+ return 0;
+}
+
+/* Put a page in the cache.
+ If it's already there, it is updated. */
+
+
+static struct vt_page * cache_put(struct cache *ca, struct vt_page *vtp)
+{
+ struct cache_page *cp;
+ int h = hash(vtp->pgno);
+
+ for (cp = PTR ca->hash[h].first; cp->node->next; cp = PTR cp->node->next)
+ if (cp->page->pgno == vtp->pgno && cp->page->subno == vtp->subno)
+ break;
+
+ if (cp->node->next)
+ {
+ // move to front.
+ dl_insert_first(ca->hash + h, dl_remove(cp->node));
+ if (ca->erc)
+ do_erc(cp->page, vtp);
+ }
+ else
+ {
+ cp = malloc(sizeof(*cp));
+ if (cp == 0)
+ return 0;
+ if (vtp->subno >= ca->hi_subno[vtp->pgno])
+ ca->hi_subno[vtp->pgno] = vtp->subno + 1;
+ ca->npages++;
+ dl_insert_first(ca->hash + h, cp->node);
+ }
+
+ *cp->page = *vtp;
+ return cp->page;
+}
+
+/* Same as cache_get but doesn't make the found entry new */
+
+
+static struct vt_page * cache_lookup(struct cache *ca, int pgno, int subno)
+{
+ struct cache_page *cp;
+ int h = hash(pgno);
+
+ for (cp = PTR ca->hash[h].first; cp->node->next; cp = PTR cp->node->next)
+ if (cp->page->pgno == pgno)
+ if (subno == ANY_SUB || cp->page->subno == subno)
+ return cp->page;
+ return 0;
+}
+
+
+static struct vt_page * cache_foreach_pg(struct cache *ca, int pgno, int subno,
+ int dir, int (*func)(), void *data)
+{
+ struct vt_page *vtp, *s_vtp = 0;
+
+ if (ca->npages == 0)
+ return 0;
+
+ if (vtp = cache_lookup(ca, pgno, subno))
+ subno = vtp->subno;
+ else if (subno == ANY_SUB)
+ subno = dir < 0 ? 0 : 0xffff;
+
+ for (;;)
+ {
+ subno += dir;
+ while (subno < 0 || subno >= ca->hi_subno[pgno])
+ {
+ pgno += dir;
+ if (pgno < 0x100)
+ pgno = 0x9ff;
+ if (pgno > 0x9ff)
+ pgno = 0x100;
+ subno = dir < 0 ? ca->hi_subno[pgno] - 1 : 0;
+ }
+ if (vtp = cache_lookup(ca, pgno, subno))
+ {
+ if (s_vtp == vtp)
+ return 0;
+ if (s_vtp == 0)
+ s_vtp = vtp;
+ if (func(data, vtp))
+ return vtp;
+ }
+ }
+}
+
+
+static int cache_mode(struct cache *ca, int mode, int arg)
+{
+ int res = -1;
+
+ switch (mode)
+ {
+ case CACHE_MODE_ERC:
+ res = ca->erc;
+ ca->erc = arg ? 1 : 0;
+ break;
+ }
+ return res;
+}
+
+
+static struct cache_ops cops =
+{
+ cache_close,
+ cache_get,
+ cache_put,
+ cache_reset,
+ cache_foreach_pg,
+ cache_mode,
+};
+
+
+struct cache * cache_open(void)
+{
+ struct cache *ca;
+ struct vt_page *vtp;
+ int i;
+
+ if (not(ca = malloc(sizeof(*ca))))
+ goto fail1;
+
+ for (i = 0; i < HASH_SIZE; ++i)
+ dl_init(ca->hash + i);
+
+ memset(ca->hi_subno, 0, sizeof(ca->hi_subno));
+ ca->erc = 1;
+ ca->npages = 0;
+ ca->op = &cops;
+
+ for (vtp = help_pages; vtp < help_pages + nr_help_pages; vtp++)
+ cache_put(ca, vtp);
+
+ return ca;
+
+fail2:
+ free(ca);
+fail1:
+ return 0;
+}