X-Git-Url: https://git.tokkee.org/?p=sysdb.git;a=blobdiff_plain;f=src%2Finclude%2Fcore%2Fdata.h;h=558e1668272e327f4719ac041c9faa28af8a80e7;hp=ffddf979f5509593417c80d6b3358b0b75e27a34;hb=6f1ea6365001d494aa358727ac031966dad4d426;hpb=47f31649186ace5c6cfe6742647dbb710c0f58e8

diff --git a/src/include/core/data.h b/src/include/core/data.h
index ffddf97..558e166 100644
--- a/src/include/core/data.h
+++ b/src/include/core/data.h
@@ -31,6 +31,7 @@
 #include "core/time.h"
 
 #include <inttypes.h>
+#include <stdbool.h>
 #include <stddef.h>
 
 #include <sys/types.h>
@@ -41,44 +42,72 @@ extern "C" {
 #endif
 
 enum {
-	SDB_TYPE_INTEGER = 1,
+	SDB_TYPE_NULL = 0,
+	SDB_TYPE_BOOLEAN,
+	SDB_TYPE_INTEGER,
 	SDB_TYPE_DECIMAL,
 	SDB_TYPE_STRING,
 	SDB_TYPE_DATETIME,
 	SDB_TYPE_BINARY,
 	SDB_TYPE_REGEX, /* extended, case-insensitive POSIX regex */
+
+	/* flags: */
+	SDB_TYPE_ARRAY = 1 << 8,
 };
 
 #define SDB_TYPE_TO_STRING(t) \
-	(((t) == SDB_TYPE_INTEGER) ? "INTEGER" \
+	(((t) == SDB_TYPE_NULL) ? "NULL" \
+		: ((t) == SDB_TYPE_BOOLEAN) ? "BOOLEAN" \
+		: ((t) == SDB_TYPE_INTEGER) ? "INTEGER" \
 		: ((t) == SDB_TYPE_DECIMAL) ? "DECIMAL" \
 		: ((t) == SDB_TYPE_STRING) ? "STRING" \
 		: ((t) == SDB_TYPE_DATETIME) ? "DATETIME" \
 		: ((t) == SDB_TYPE_BINARY) ? "BINARY" \
-		: ((t) == SDB_TYPE_REGEX) ? "REGEX" : "UNKNOWN")
+		: ((t) == SDB_TYPE_REGEX) ? "REGEX" \
+		: ((t) == (SDB_TYPE_ARRAY | SDB_TYPE_BOOLEAN)) ? "[]BOOLEAN" \
+		: ((t) == (SDB_TYPE_ARRAY | SDB_TYPE_INTEGER)) ? "[]INTEGER" \
+		: ((t) == (SDB_TYPE_ARRAY | SDB_TYPE_DECIMAL)) ? "[]DECIMAL" \
+		: ((t) == (SDB_TYPE_ARRAY | SDB_TYPE_STRING)) ? "[]STRING" \
+		: ((t) == (SDB_TYPE_ARRAY | SDB_TYPE_DATETIME)) ? "[]DATETIME" \
+		: ((t) == (SDB_TYPE_ARRAY | SDB_TYPE_BINARY)) ? "[]BINARY" \
+		: ((t) == (SDB_TYPE_ARRAY | SDB_TYPE_REGEX)) ? "[]REGEX" \
+		: "UNKNOWN")
+
+union sdb_datum;
+typedef union sdb_datum sdb_datum_t;
+
+union sdb_datum {
+	bool        boolean;  /* SDB_TYPE_BOOLEAN */
+	int64_t     integer;  /* SDB_TYPE_INTEGER */
+	double      decimal;  /* SDB_TYPE_DECIMAL */
+	char       *string;   /* SDB_TYPE_STRING  */
+	sdb_time_t  datetime; /* SDB_TYPE_DATETIME */
+	struct {
+		size_t length;
+		unsigned char *datum;
+	} binary;             /* SDB_TYPE_BINARY */
+	struct {
+		char *raw;
+		regex_t regex;
+	} re;                 /* SDB_TYPE_REGEX */
+
+	struct {
+		size_t length;
+		void *values;
+	} array;
+};
 
 /*
  * sdb_data_t:
- * A datum retrieved from an arbitrary data source.
+ * An arbitrary value of a specified type.
  */
 typedef struct {
-	int type;
-	union {
-		int64_t     integer;  /* SDB_TYPE_INTEGER */
-		double      decimal;  /* SDB_TYPE_DECIMAL */
-		char       *string;   /* SDB_TYPE_STRING  */
-		sdb_time_t  datetime; /* SDB_TYPE_DATETIME */
-		struct {
-			size_t length;
-			unsigned char *datum;
-		} binary;             /* SDB_TYPE_BINARY */
-		struct {
-			char *raw;
-			regex_t regex;
-		} re;                 /* SDB_TYPE_REGEX */
-	} data;
+	int type;  /* type of the datum */
+	sdb_datum_t data;
 } sdb_data_t;
-#define SDB_DATA_INIT { 0, { .integer = 0 } }
+#define SDB_DATA_INIT { SDB_TYPE_NULL, { .integer = 0 } }
+
+extern const sdb_data_t SDB_DATA_NULL;
 
 /*
  * sdb_data_copy:
@@ -135,11 +164,38 @@ sdb_data_strcmp(const sdb_data_t *d1, const sdb_data_t *d2);
 /*
  * sdb_data_isnull:
  * Determine whether a datum is NULL. A datum is considered to be NULL if
- * either datum is NULL or if the string or binary datum is NULL.
+ * either datum is NULL or if the type is SDB_TYPE_NULL or if the string or
+ * binary datum is NULL.
  */
-_Bool
+bool
 sdb_data_isnull(const sdb_data_t *datum);
 
+/*
+ * sdb_data_inarray:
+ * Determine whether a datum is included in an array based on the usual
+ * comparison function of the value's type. The element type of the array has
+ * to match the type of the value. The value may be another array. In that
+ * case, the element types have to match and the function returns true if all
+ * elements of the first array are included in the second where order does not
+ * matter.
+ */
+bool
+sdb_data_inarray(const sdb_data_t *value, const sdb_data_t *array);
+
+/*
+ * sdb_data_array_get:
+ * Get the i-th value stored in the specified array and store an alias in
+ * 'value'. Storing an alias means that the value points to the actual array
+ * element. Do *not* free the value after using it (i.e., don't use
+ * sdb_data_free_datum).
+ *
+ * Returns:
+ *  - 0 on success
+ *  - a negative value else
+ */
+int
+sdb_data_array_get(const sdb_data_t *array, size_t i, sdb_data_t *value);
+
 /*
  * Operators supported by sdb_data_eval_expr.
  */
@@ -179,6 +235,8 @@ sdb_data_parse_op(const char *op);
  * support the other operators. The result may be allocated dynamically and
  * has to be freed by the caller (using sdb_data_free_datum).
  *
+ * If any of the data points is a NULL value, the result is also NULL.
+ *
  * The data-types of d1 and d2 have to be the same, except for the following
  * cases:
  *  - <integer> or <decimal> <mul> <datetime>
@@ -192,6 +250,23 @@ int
 sdb_data_expr_eval(int op, const sdb_data_t *d1, const sdb_data_t *d2,
 		sdb_data_t *res);
 
+/*
+ * sdb_data_expr_type:
+ * Determine the type of the expression when applying the specified operator
+ * to the specified types. Note that if an actual value is a typed NULL value
+ * (e.g. a NULL string value), the return value of this function does not
+ * match the return type of sdb_data_expr_eval.
+ *
+ * See the documentation of sdb_data_expr_eval() for a description of which
+ * operations are supported.
+ *
+ * Returns:
+ *  - the type id on success
+ *  - a negative value else
+ */
+int
+sdb_data_expr_type(int op, int type1, int type2);
+
 /*
  * sdb_data_strlen:
  * Returns a (worst-case) estimate for the number of bytes required to format
@@ -219,9 +294,8 @@ enum {
  *  - the number of characters written to the buffer (excluding the terminated
  *    null byte) or the number of characters which would have been written in
  *    case the output was truncated
- *  - a negative value else
  */
-int
+size_t
 sdb_data_format(const sdb_data_t *datum, char *buf, size_t buflen, int quoted);
 
 /*
@@ -232,24 +306,27 @@ sdb_data_format(const sdb_data_t *datum, char *buf, size_t buflen, int quoted);
  * character of the string is "0"), sedecimal (base 16, if the string includes
  * the "0x" prefix), or decimal. Decimal numbers may also be "infinity" or
  * "NaN" or may use a decimal exponent. Date-time values are expected to be
- * specified as (floating point) number of seconds since the epoch. For string
- * and binary data, the input string is passed to the datum. The function does
- * not allocate new memory for that purpose. Use sdb_data_copy() if you want
- * to do that. For regex data, the input string is copied to newly allocated
- * memory and also compiled to a regex. Use sdb_data_free_datum() to free the
- * dynamically allocated memory.
- *
- * The input string may be stored in 'data', that is, the function may be used
- * to do an inline cast from a string to any other type. It is the callers
- * responsibility to free the memory used by the string in case the target
- * type does not keep a reference to it.
+ * specified as (floating point) number of seconds since the epoch. New memory
+ * will be allocated as necessary and will have to be free'd using
+ * sdb_data_free_datum().
  *
  * Returns:
  *  - 0 on success
  *  - a negative value else
  */
 int
-sdb_data_parse(char *str, int type, sdb_data_t *data);
+sdb_data_parse(const char *str, int type, sdb_data_t *data);
+
+/*
+ * sdb_data_sizeof:
+ * Return the size of the data-type identified by the specified type.
+ *
+ * Returns:
+ *  - the size of the data-type on success
+ *  - 0 else
+ */
+size_t
+sdb_data_sizeof(int type);
 
 #ifdef __cplusplus
 } /* extern "C" */