X-Git-Url: https://git.tokkee.org/?a=blobdiff_plain;f=src%2Finclude%2Fcore%2Fdata.h;h=cfdf48db8ea7d63fd1c2ef718901706bd10ca2e0;hb=c5e7e465a3ec8eccfd881411f08244d8c5265660;hp=53b68193dae4765eb432565992c5d8d8cd208fe6;hpb=3cf471eb9fca92232ef595525d21344313135eb8;p=sysdb.git diff --git a/src/include/core/data.h b/src/include/core/data.h index 53b6819..cfdf48d 100644 --- a/src/include/core/data.h +++ b/src/include/core/data.h @@ -1,6 +1,6 @@ /* * SysDB - src/include/core/data.h - * Copyright (C) 2012 Sebastian 'tokkee' Harl + * Copyright (C) 2012-2014 Sebastian 'tokkee' Harl * All rights reserved. * * Redistribution and use in source and binary forms, with or without @@ -33,42 +33,76 @@ #include #include +#include +#include + #ifdef __cplusplus extern "C" { #endif enum { - SDB_TYPE_INTEGER = 1, + SDB_TYPE_NULL = 0, + 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_DECIMAL) ? "DECIMAL" \ + : ((t) == SDB_TYPE_STRING) ? "STRING" \ + : ((t) == SDB_TYPE_DATETIME) ? "DATETIME" \ + : ((t) == SDB_TYPE_BINARY) ? "BINARY" \ + : ((t) == SDB_TYPE_REGEX) ? "REGEX" : "UNKNOWN") + +union sdb_datum; +typedef union sdb_datum sdb_datum_t; + +union sdb_datum { + 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 */ - } data; + int type; /* type of the datum */ + sdb_datum_t data; } sdb_data_t; +#define SDB_DATA_INIT { SDB_TYPE_NULL, { .integer = 0 } } + +extern const sdb_data_t SDB_DATA_NULL; /* * sdb_data_copy: * Copy the datum stored in 'src' to the memory location pointed to by 'dst'. * Any dynamic data (strings, binary data) is copied to newly allocated * memory. Use, for example, sdb_data_free_datum() to free any dynamic memory - * stored in a datum. + * stored in a datum. On error, 'dst' is unchanged. Else, any dynamic memory + * in 'dst' will be freed. * * Returns: * - 0 on success @@ -80,13 +114,173 @@ sdb_data_copy(sdb_data_t *dst, const sdb_data_t *src); /* * sdb_data_free_datum: * Free any dynamic memory referenced by the specified datum. Does not free - * the memory allocated for the sdb_data_t object itself. This function must + * the memory allocated by the sdb_data_t object itself. This function must * not be used if any static or stack memory is referenced from the data * object. */ void sdb_data_free_datum(sdb_data_t *datum); +/* + * sdb_data_cmp: + * Compare two data points. A NULL datum is considered less than any non-NULL + * datum. On data-type mismatch, the function always returns a non-zero value. + * + * Returns: + * - a value less than zero if d1 compares less than d2 + * - zero if d1 compares equal to d2 + * - a value greater than zero if d1 compares greater than d2 + */ +int +sdb_data_cmp(const sdb_data_t *d1, const sdb_data_t *d2); + +/* + * sdb_data_strcmp: + * Compare the string values of two data points. A NULL datum is considered + * less than any non-NULL. This function works for arbitrary combination of + * data-types. + * + * Returns: + * - a value less than zero if d1 compares less than d2 + * - zero if d1 compares equal to d2 + * - a value greater than zero if d1 compares greater than d2 + */ +int +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 type is SDB_TYPE_NULL or if the string or + * binary datum is NULL. + */ +_Bool +sdb_data_isnull(const sdb_data_t *datum); + +/* + * Operators supported by sdb_data_eval_expr. + */ +enum { + SDB_DATA_ADD = 1, /* addition */ + SDB_DATA_SUB, /* substraction */ + SDB_DATA_MUL, /* multiplication */ + SDB_DATA_DIV, /* division */ + SDB_DATA_MOD, /* modulo */ + SDB_DATA_CONCAT, /* string / binary data concatenation */ +}; + +#define SDB_DATA_OP_TO_STRING(op) \ + (((op) == SDB_DATA_ADD) ? "+" \ + : ((op) == SDB_DATA_SUB) ? "-" \ + : ((op) == SDB_DATA_MUL) ? "*" \ + : ((op) == SDB_DATA_DIV) ? "/" \ + : ((op) == SDB_DATA_MOD) ? "%" \ + : ((op) == SDB_DATA_CONCAT) ? "||" : "UNKNOWN") + +/* + * sdb_data_parse_op: + * Parse the string representation of an operator supported by + * sdb_data_expr_eval. + * + * Returns: + * - the ID of the operator + * - a negative value in case the operator does not exist + */ +int +sdb_data_parse_op(const char *op); + +/* + * sdb_data_expr_eval: + * Evaluate a simple arithmetic expression on two data points. String and + * binary data only support concatenation and all other data types only + * 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: + * - or + * - or
or or + * + * Returns: + * - 0 on success + * - a negative value else + */ +int +sdb_data_expr_eval(int op, const sdb_data_t *d1, const sdb_data_t *d2, + sdb_data_t *res); + +/* + * sdb_data_strlen: + * Returns a (worst-case) estimate for the number of bytes required to format + * the datum as a string. Does not take the terminating null byte into + * account. + */ +size_t +sdb_data_strlen(const sdb_data_t *datum); + +enum { + SDB_UNQUOTED = 0, + SDB_SINGLE_QUOTED, + SDB_DOUBLE_QUOTED, +}; + +/* + * sdb_data_format: + * Output the specified datum to the specified string using a default format. + * The value of 'quoted' determines whether and how non-integer and + * non-decimal values are quoted. If the buffer size is less than the return + * value of sdb_data_strlen, the datum may be truncated. The buffer will + * always be nul-terminated after calling this function. + * + * Returns: + * - 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 +sdb_data_format(const sdb_data_t *datum, char *buf, size_t buflen, int quoted); + +/* + * sdb_data_parse: + * Parse the specified string into a datum using the specified type. The + * string value is expected to be a raw value of the specified type. Integer + * and decimal numbers may be signed or unsigned octal (base 8, if the first + * 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. + * + * Returns: + * - 0 on success + * - a negative value else + */ +int +sdb_data_parse(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" */ #endif