improve mime handling

we still have an hardcoded list, but this implements the API needed to
modify the mappings.

1 files changed, 116 insertions, 0 deletions

diff --git a/mime.c b/mime.c
new file mode 100644
index 0000000..cb2f28a
--- /dev/null
+++ b/mime.c
@@ -0,0 +1,116 @@
+/*
+ * Copyright (c) 2021 Omar Polo <op@omarpolo.com>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include <errno.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "gmid.h"
+
+struct etm {			/* extension to mime */
+	const char	*mime;
+	const char	*ext;
+};
+
+struct mimes {
+	struct etm	*t;
+	size_t		len;
+	size_t		cap;
+};
+
+struct mimes mimes;
+
+void
+init_mime(void)
+{
+	mimes.len = 0;
+	mimes.cap = 2;
+
+	if ((mimes.t = calloc(mimes.cap, sizeof(struct etm))) == NULL)
+		fatal("calloc: %s", strerror(errno));
+}
+
+/* register mime for the given extension */
+void
+add_mime(const char *mime, const char *ext)
+{
+	if (mimes.len == mimes.cap) {
+		mimes.cap *= 1.5;
+		mimes.t = realloc(mimes.t, mimes.cap * sizeof(struct etm));
+		if (mimes.t == NULL)
+			fatal("realloc: %s", strerror(errno));
+	}
+
+	mimes.t[mimes.len].mime = mime;
+	mimes.t[mimes.len].ext  = ext;
+	mimes.len++;
+}
+
+/* load a default set of common mime-extension associations */
+void
+load_default_mime()
+{
+	struct etm *i, m[] = {
+		{"application/pdf",	"pdf"},
+		{"image/gif",		"gif"},
+		{"image/jpeg",		"jpg"},
+		{"image/jpeg",		"jpeg"},
+		{"image/png",		"png"},
+		{"image/svg+xml",	"svg"},
+		{"text/gemini",		"gemini"},
+		{"text/gemini",		"gmi"},
+		{"text/markdown",	"markdown"},
+		{"text/markdown",	"md"},
+		{"text/plain",		"txt"},
+		{"text/xml",		"xml"},
+		{NULL, NULL}
+	};
+
+	for (i = m; i->mime != NULL; ++i)
+		add_mime(i->mime, i->ext);
+}
+
+static const char *
+path_ext(const char *path)
+{
+	const char *end;
+
+	end = path + strlen(path)-1;
+	for (; end != path; --end) {
+		if (*end == '.')
+			return end+1;
+		if (*end == '/')
+			break;
+	}
+
+	return NULL;
+}
+
+const char *
+mime(const char *path)
+{
+	const char *ext, *def = "application/octet-stream";
+	struct etm *t;
+
+	if ((ext = path_ext(path)) == NULL)
+		return def;
+
+	for (t = mimes.t; t->mime != NULL; ++t)
+		if (!strcmp(ext, t->ext))
+			return t->mime;
+
+	return def;
+}