Replace SongList with struct songvec

Our linked-list implementation is wasteful and the
SongList isn't modified enough to benefit from being a linked
list.  So use a more compact array of song pointers which
saves ~200K on a library with ~9K songs (on x86-32).

1 files changed, 89 insertions, 0 deletions

diff --git a/src/songvec.c b/src/songvec.c
new file mode 100644
index 000000000..620338781
--- /dev/null
+++ b/src/songvec.c
@@ -0,0 +1,89 @@
+#include "songvec.h"
+#include "utils.h"
+
+/* Only used for sorting/searchin a songvec, not general purpose compares */
+static int songvec_cmp(const void *s1, const void *s2)
+{
+	const Song *a = ((const Song * const *)s1)[0];
+	const Song *b = ((const Song * const *)s2)[0];
+	return strcmp(a->url, b->url);
+}
+
+static size_t sv_size(struct songvec *sv)
+{
+	return sv->nr * sizeof(Song *);
+}
+
+void songvec_sort(struct songvec *sv)
+{
+	qsort(sv->base, sv->nr, sizeof(Song *), songvec_cmp);
+}
+
+Song *songvec_find(struct songvec *sv, const char *url)
+{
+	int i;
+
+	for (i = sv->nr; --i >= 0; )
+		if (!strcmp(sv->base[i]->url, url))
+			return sv->base[i];
+	return NULL;
+}
+
+int songvec_delete(struct songvec *sv, Song *del)
+{
+	int i;
+
+	for (i = sv->nr; --i >= 0; ) {
+		if (sv->base[i] != del)
+			continue;
+		/* we _don't_ call freeSong() here */
+		if (!--sv->nr) {
+			free(sv->base);
+			sv->base = NULL;
+		} else {
+			memmove(&sv->base[i], &sv->base[i + 1],
+				(sv->nr - i + 1) * sizeof(Song *));
+			sv->base = xrealloc(sv->base, sv_size(sv));
+		}
+		return i;
+	}
+
+	return -1; /* not found */
+}
+
+void songvec_add(struct songvec *sv, Song *add)
+{
+	++sv->nr;
+	sv->base = xrealloc(sv->base, sv_size(sv));
+	sv->base[sv->nr - 1] = add;
+}
+
+void songvec_free(struct songvec *sv)
+{
+	free(sv->base);
+	sv->base = NULL;
+	sv->nr = 0;
+}
+
+/*
+ * Removes missing songs from a songvec. This function is only temporary
+ * as updating will be moved into a thread and updating shared memory...
+ */
+#include "path.h"
+#include "ls.h"
+void songvec_prune(struct songvec *sv)
+{
+	int i;
+	char tmp[MPD_PATH_MAX];
+	struct stat sb;
+
+	for (i = sv->nr; --i >= 0; ) {
+		Song *song = sv->base[i];
+		assert(song);
+		if (!myStat(get_song_url(tmp, song), &sb))
+			continue;
+		songvec_delete(sv, song);
+		freeSong(song);
+		i = sv->nr;
+	}
+}