Imported Upstream version 0.8.0~pre1upstream/0.8.0_pre1

1 files changed, 196 insertions, 0 deletions

diff --git a/src/libknot/util/utils.h b/src/libknot/util/utils.h
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+/*!
+ * \file utils.h
+ *
+ * \author Lubos Slovak <lubos.slovak@nic.cz>
+ *
+ * \brief Various utilities.
+ *
+ * \addtogroup libknot
+ * @{
+ */
+/*  Copyright (C) 2011 CZ.NIC, z.s.p.o. <knot-dns@labs.nic.cz>
+
+    This program is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef _KNOT_UTILS_H_
+#define _KNOT_UTILS_H_
+
+#include <string.h>
+#include <stdint.h>
+#include <stdio.h>
+
+/*!
+ * \brief A general purpose lookup table.
+ *
+ * \note Taken from NSD.
+ */
+struct knot_lookup_table {
+	int id;
+	const char *name;
+};
+
+typedef struct knot_lookup_table knot_lookup_table_t;
+
+/*!
+ * \brief Looks up the given name in the lookup table.
+ *
+ * \param table Lookup table.
+ * \param name Name to look up.
+ *
+ * \return Item in the lookup table with the given name or NULL if no such is
+ *         present.
+ */
+knot_lookup_table_t *knot_lookup_by_name(knot_lookup_table_t *table,
+                                             const char *name);
+
+/*!
+ * \brief Looks up the given id in the lookup table.
+ *
+ * \param table Lookup table.
+ * \param id ID to look up.
+ *
+ * \return Item in the lookup table with the given id or NULL if no such is
+ *         present.
+ */
+knot_lookup_table_t *knot_lookup_by_id(knot_lookup_table_t *table,
+                                           int id);
+
+/*!
+ * \brief Strlcpy - safe string copy function, based on FreeBSD implementation.
+ *
+ * http://www.openbsd.org/cgi-bin/cvsweb/src/lib/libc/string/
+ *
+ * \param dst Destination string.
+ * \param src Source string.
+ * \param size How many characters to copy - 1.
+ *
+ * \return strlen(src), if retval >= siz, truncation occurred.
+ */
+size_t knot_strlcpy(char *dst, const char *src, size_t size);
+
+/*
+ * Writing / reading arbitrary data to / from wireformat.
+ */
+
+/*!
+ * \brief Reads 2 bytes from the wireformat data.
+ *
+ * \param pos Data to read the 2 bytes from.
+ *
+ * \return The 2 bytes read, in inverse endian.
+ */
+static inline uint16_t knot_wire_read_u16(const uint8_t *pos)
+{
+	return (pos[0] << 8) | pos[1];
+}
+
+/*!
+ * \brief Reads 4 bytes from the wireformat data.
+ *
+ * \param pos Data to read the 4 bytes from.
+ *
+ * \return The 4 bytes read, in inverse endian.
+ */
+static inline uint32_t knot_wire_read_u32(const uint8_t *pos)
+{
+	return (pos[0] << 24) | (pos[1] << 16) | (pos[2] << 8) | pos[3];
+}
+
+/*!
+ * \brief Reads 6 bytes from the wireformat data.
+ *
+ * \param pos Data to read the 6 bytes from.
+ *
+ * \return The 6 bytes read, in inverse endian.
+ */
+static inline uint64_t knot_wire_read_u48(const uint8_t *pos)
+{
+	return ((uint64_t)(pos[0]) << 40) | ((uint64_t)(pos[1]) << 32) | (pos[2] << 24) |
+	        (pos[3] << 16) | (pos[4] << 8) | pos[5];
+}
+
+/*!
+ * \brief Writes 2 bytes in wireformat.
+ *
+ * The endian of the data is inverted.
+ *
+ * \param pos Position where to put the 2 bytes.
+ * \param data Data to put.
+ */
+static inline void knot_wire_write_u16(uint8_t *pos, uint16_t data)
+{
+	pos[0] = (uint8_t)((data >> 8) & 0xff);
+	pos[1] = (uint8_t)(data & 0xff);
+}
+
+/*!
+ * \brief Writes 4 bytes in wireformat.
+ *
+ * The endian of the data is inverted.
+ *
+ * \param pos Position where to put the 4 bytes.
+ * \param data Data to put.
+ */
+static inline void knot_wire_write_u32(uint8_t *pos, uint32_t data)
+{
+	pos[0] = (uint8_t)((data >> 24) & 0xff);
+	pos[1] = (uint8_t)((data >> 16) & 0xff);
+	pos[2] = (uint8_t)((data >> 8) & 0xff);
+	pos[3] = (uint8_t)(data & 0xff);
+}
+
+/*!
+ * \brief Writes 6 bytes in wireformat.
+ *
+ * The endian of the data is inverted.
+ *
+ * \param pos Position where to put the 4 bytes.
+ * \param data Data to put.
+ */
+static inline void knot_wire_write_u48(uint8_t *pos, uint64_t data)
+{
+	pos[0] = (uint8_t)((data >> 40) & 0xff);
+	pos[1] = (uint8_t)((data >> 32) & 0xff);
+	pos[2] = (uint8_t)((data >> 24) & 0xff);
+	pos[3] = (uint8_t)((data >> 16) & 0xff);
+	pos[4] = (uint8_t)((data >> 8) & 0xff);
+	pos[5] = (uint8_t)(data & 0xff);
+}
+
+/*!
+ * \brief Linear congruential generator.
+ *
+ * Simple pseudorandom generator for general purpose.
+ * \warning Do not use for cryptography.
+ * \return Random number <0, (size_t)~0>
+ */
+size_t knot_quick_rand();
+
+uint16_t knot_random_id();
+
+/*!
+ * \brief Helper function for simple locking.
+ *
+ * \param type Type of lock.
+ * \param type Starting position of lock.
+ *
+ * \return Locking structure.
+ */
+struct flock* knot_file_lock(short type, short whence);
+
+#endif /* _KNOT_UTILS_H_ */
+
+/*! @} */
+