Workload parameters

These declarations used to provide module description to server
and simply parse workload parameters in JSON format.

Each parameter declaration has:
- type @see wlp_type_t
- limitations (like string max length, number range, possible values, etc.) @see wlp_range_t and macroses
- name and description (text)
- offset in control structure which is used during parsing

Parameter declaration are saved as array of wlp_descr_t structures with "NULL-terminator" with type WLP_NULL.

Workload parameter generators

Some of workload parameters may be set on per-request basis. For example,
disk i/o generator with random or sequental access to blocks needs number
of block per each request. Thus, it would be generated in this module.

There are two main generators:

• WLPG_VALUE - uses same value would be used for all requests. If
  value is omitted in config, wlpgen will try to use default value.
  
• WLPG_RANDOM - like it's name says, it will generate value per each
  request using random generators and variators.
  
• for integer and float wlparam types it will take pure generator/variator value
  
• for other wlparam types it uses probability map and random generator only
  

Constants

WLPF_OUTPUT, WLPF_REQUEST, WLPF_NO_FLAGS, WLPF_OPTIONAL

Workload parameter flags

#define WLPF_NO_FLAGS   0x00
#define WLPF_OPTIONAL   0x01
#define WLPF_REQUEST    0x02
#define WLPF_OUTPUT (WLPF_REQUEST | 0x04)

Functions

WLP_NO_RANGE, WLP_STRING_SET_RANGE, WLP_FLOAT_RANGE, WLP_INT_RANGE, WLP_STRING_LENGTH

Range declaration

#define WLP_NO_RANGE()
#define WLP_STRING_LENGTH(length)
#define WLP_INT_RANGE(min, max)
#define WLP_FLOAT_RANGE(min, max)
#define WLP_STRING_SET_RANGE(set)

WLP_FLOAT_DEFAULT, WLP_STRING_SET_DEFAULT, WLP_NO_DEFAULT, WLP_INT_DEFAULT, WLP_STRING_DEFAULT, WLP_BOOLEAN_DEFAULT

Default wl parameter value

#define WLP_NO_DEFAULT()
#define WLP_BOOLEAN_DEFAULT(b)
#define WLP_INT_DEFAULT(i)
#define WLP_FLOAT_DEFAULT(f)
#define WLP_STRING_DEFAULT(s)
#define WLP_STRING_SET_DEFAULT(ssi)

wlp_get_base_type

public

LIBEXPORT wlp_type_t wlp_get_base_type(wlp_descr_t* wlp)

wlpgen_generate

Generate request parameter structure for workload wl

ARGUMENTS

• wl - workload
  

RETURN VALUES
pointer to that structure or NULL if no request params exist for this workload type

NOTES
structure is freed on wl_request_destroy()

void* wlpgen_generate(struct workload* wl)

Types

Workload parameter type definitions

typedef int64_t     wlp_integer_t;

typedef double      wlp_float_t;

typedef char        wlp_string_t;

typedef boolean_t   wlp_bool_t;

typedef int         wlp_strset_t;

typedef void*       wlp_hiobject_t;

wlp_type_t

Workload parameter type hint.

When TSLoad generates a value that is passed to a module as a workload or a request
parameter, it relies on that hint to correctly handle incoming value and write it to
memory.

There are "base" types which define that factors but doesn't know nature of a
value and a "meta" types that add meaning to a value. Meta-types rely on a corresponding
base value in how they handled but add some meaning to values.

I.e. there is WLP_INTEGER that is used for keeping integers (base type) that expect
"integer" number from config and wlp_integer_t residing in data structure. But if it
represent a size (i.e. size of disk block) it is reasonable to use WLP_SIZE - metatype
that has same constraints as WLP_INTEGER but may provide nice formatting (i.e. "8 kb")
in some cases.

VALUES

• WLP_NULL - Special value - used to mark end of parameter list
  
• WLP_TYPE_MAX - Special value - maximum number of types
  
• WLP_BOOL - Boolean type (wlp_bool_t)
  
• WLP_INTEGER - Integer numbers (wlp_integer_t)
  
• WLP_FLOAT - Floating point number (wlp_float_t)
  
• WLP_RAW_STRING - String, statically allocated (char). Use range to provide its length
  
• WLP_STRING_SET - Enumeration (int/wlp_strset_t) - parses incoming string and picks index of it in array defined by range.
  
• WLP_SIZE - Volume of digital information in bytes (wlp_integer_t)
  
• WLP_TIME - Time intervals (ts_time_t)
  
• WLP_FILE_PATH - Path on a file system (char)
  
• WLP_CPU_OBJECT - HostInfo object representing a processor object (hi_object_t*)
  
• WLP_DISK - HostInfo object representing a disk, volume, etc. (hi_object_t*)
  

typedef enum {
    WLP_NULL,

    WLP_BOOL,
    WLP_INTEGER,
    WLP_FLOAT,
    WLP_RAW_STRING,     /*Any string*/

    WLP_STRING_SET,      /*string - one of possible values*/

    /* metatypes - using primitive types in serialization
     * but have different meanings */
    WLP_SIZE,
    WLP_TIME,

    WLP_FILE_PATH,
    WLP_CPU_OBJECT,
    WLP_DISK,

    WLP_TYPE_MAX,

    WLP_HI_OBJECT        /* Base type - not really used */
} wlp_type_t;

wlp_range_t

typedef struct {
    boolean_t range;        /*enabled flag*/

    /* Here should be union, but because of some smart people, who decided that
     * | ISO C++03 8.5.1[dcl.init.aggr]/15:
     * | When a union is initialized with a brace-enclosed initializer,
     * | the braces shall only contain an initializer for the first member of the union.
     * and another smart people from Microsoft who ignoring C99 compliance
     * we will waste memory to provide nice macros like WLP_STRING_LENGTH
     *  */
    struct {
        /*WLP_RAW_STRING*/
        struct {
            unsigned str_length;
        };
        /*WLP_INTEGER*/
        struct {
            wlp_integer_t i_min;
            wlp_integer_t i_max;
        };
        /*WLP_FLOAT*/
        struct {
            wlp_float_t d_min;
            wlp_float_t d_max;
        };
        /*WLP_STRING_SET*/
        struct {
            int ss_num;
            const char** ss_strings;
        };
    };
} wlp_range_t;

wlp_default_t

typedef struct {
    boolean_t enabled;

    wlp_bool_t b;
    wlp_integer_t i;
    wlp_float_t f;
    const char* s;
    wlp_strset_t ssi;
} wlp_default_t;

wlp_descr_t

Workload parameter descriptor

MEMBERS

• type - Parameter type hint
  
• flags - Parameter flags
  
• range - Pre-defined range of acceptable parameter values. If set, TSLoad will pre-check value passed from config or a server and will raise an error, if it is outside this range.
  
• defval - Default value of parameter. Could be a hint, or if WLPF_OPTIONAL flag is set, could really be a default value that would be used if parameter is omitted from config.
  
• name - Name of parameter
  
• description - Description of a parameter
  
• off - Offset in data structure where param value would be written
  

typedef struct {
    wlp_type_t type;
    unsigned long flags;

    wlp_range_t range;
    wlp_default_t defval;

    const char* name;
    const char* description;

    size_t off;
} wlp_descr_t;

typedef enum wlpgen_type

typedef enum wlpgen_type {
    WLPG_VALUE,
    WLPG_RANDOM
} wlpgen_type_t;

typedef union wlpgen_value

typedef union wlpgen_value {
    char value[16];
    char* string;
} wlpgen_value_t;

wlpgen_probability_t

typedef struct {
    wlpgen_value_t  value;

    wlpgen_value_t* valarray;
    int                length;

    double probability;
} wlpgen_probability_t;

typedef struct wlpgen_randgen

typedef struct wlpgen_randgen {
    randgen_t*    rg;
    randvar_t*     rv;

    /* For boolean/stringset - probability map */
    int pcount;
    wlpgen_probability_t* pmap;
} wlpgen_randgen_t;

typedef struct wlp_generator

typedef struct wlp_generator {
    wlpgen_type_t type;
    wlp_descr_t* wlp;
    struct workload* wl;

    union {
        wlpgen_value_t value;
        wlpgen_randgen_t randgen;
    } generator;

    list_node_t    node;
} wlp_generator_t;