Utils

db.c

@@ -0,0 +1,92 @@
+/*	$Id$ */
+/*
+ * Copyright (c) 2016 Kristaps Dzonsons <kristaps@bsd.lv>
+ *
+ * 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 <stdarg.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <time.h>
+#include <unistd.h>
+
+#include <kcgi.h>
+#include <kcgijson.h>
+#include <sqlite3.h>
+
+#include "extern.h"
+
+/*
+ * When the database is busy or locked, sleep for a random amount of
+ * time before continuing.
+ * We could put all sorts of heuristics in here to back off, but we do
+ * something really simple.
+ */
+static void
+db_sleep(size_t attempt)
+{
+
+	if (attempt < 10)
+		usleep(arc4random_uniform(100000));
+	else
+		usleep(arc4random_uniform(500000));
+}
+
+/*
+ * Open the database and stash the resulting handle in the kreq
+ */
+int
+db_open(struct kreq *r, const char *file)
+{
+	size_t	 attempt;
+	sqlite3	*db;
+	int	 rc;
+
+	attempt = 0;
+  // TODO max attempt, return 0
+again:
+	rc = sqlite3_open(file, &db);
+	if (SQLITE_BUSY == rc) {
+		db_sleep(attempt++);
+		goto again;
+	} else if (SQLITE_LOCKED == rc) {
+		fprintf(stderr, "sqlite3_open: %s\n", 
+			sqlite3_errmsg(db));
+		db_sleep(attempt++);
+		goto again;
+	} else if (SQLITE_PROTOCOL == rc) {
+		fprintf(stderr, "sqlite3_open: %s\n", 
+			sqlite3_errmsg(db));
+		db_sleep(attempt++);
+		goto again;
+	} else if (SQLITE_OK == rc) {
+		sqlite3_busy_timeout(db, 500);
+    r->arg = sql;
+    return(1);
+	} 
+}
+
+/*
+ * Close the database stashed in the kreq's argument.
+ */
+void
+db_close(struct kreq *r)
+{
+	if (SQLITE_OK == sqlite3_close(r->arg)) {
+    r->arg = NULL;
+		return;
+  }
+	fprintf(stderr, "sqlite3_close: %s\n", sqlite3_errmsg(db));
+}

extern.h

@@ -0,0 +1,29 @@
+/*	$Id$ */
+/*
+ * Copyright (c) 2016 Kristaps Dzonsons <kristaps@bsd.lv>
+ *
+ * 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.
+ */
+#ifndef EXTERN_H
+#define EXTERN_H
+
+__BEGIN_DECLS
+
+void		 db_close(struct kreq *);
+int		 db_open(struct kreq *, const char *);
+
+void		 json_emptydoc(struct kreq *);
+
+__END_DECLS
+
+#endif

json.c

@@ -0,0 +1,41 @@
+/*	$Id$ */
+/*
+ * Copyright (c) 2016 Kristaps Dzonsons <kristaps@bsd.lv>
+ *
+ * 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 <stdarg.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+
+#include <kcgi.h>
+#include <kcgijson.h>
+
+#include "extern.h"
+
+/*
+ * Emit an empty JSON document.
+ */
+void
+json_emptydoc(struct kreq *r)
+{
+	struct kjsonreq	 req;
+
+	kjson_open(&req, r);
+	kjson_obj_open(&req);
+	kjson_obj_close(&req);
+	kjson_close(&req);
+}
+