class LWES::Event

Used for mapping LWES events in in an ESF file to a Ruby object. LWES::Event-derived classes are more memory efficient if your event definitions have many unused fields.

LWES::TypeDB#create_classes! with :sparse set to true will create classes subclassed from LWES::Event instead of LWES::Struct.

For users unable to use LWES::Listener, ::parse may also be used with UDPSocket (distributed with Ruby) to parse events:

receiver =
receiver.bind(nil, port)
buffer, addr = receiver.recvfrom(65536)
event = LWES::Event.parse(buffer)

Public Class Methods

new(src = nil) click to toggle source

Initializes a new LWES::Event. If src is given, it must be an LWES::Event or hash which the new event takes initial values from

# File lib/lwes/event.rb, line 74
def initialize(src = nil)
  src and merge! src
LWES::Event.parse(buffer) → LWES::Event click to toggle source

Parses a string buffer and returns a new LWES::Event object

static VALUE parse(VALUE self, VALUE buf)
        struct lwes_event *e;
        struct lwes_event_deserialize_tmp dtmp;
        LWES_BYTE_P bytes;
        size_t num_bytes;
        int rc;

        bytes = (LWES_BYTE_P)RSTRING_PTR(buf);
        num_bytes = (size_t)RSTRING_LEN(buf);
        e = lwes_event_create_no_name(NULL);
        rc = lwes_event_from_bytes(e, bytes, num_bytes, 0, &dtmp);
        if (rc < 0) {
                         "failed to parse LWES event (code: %d)", rc);

        return lwesrb_wrap_event(self, e);
subclass(options, &block) click to toggle source

There is no need to call this method directly. use LWES::TypeDB#create_classes! with the :sparse flag set to true.

This takes the same options as

# File lib/lwes/event.rb, line 27
def self.subclass(options, &block)
  db = type_db(options)
  dump = db.to_hash
  klass, name, event_def = class_for(options, dump)
  tmp =
  set_constants(tmp, db, klass, name, options)
  tmp.class_eval(&block) if block_given?

  meta = dump[:MetaEventInfo] || []
  methods = meta + event_def
  methods = methods.inject("") do |str, (k,_)|
    str << "def #{k}; self[:#{k}]; end\n"
    str << "def #{k}= val; self[:#{k}] = val; end\n"
  methods << "def initialize(src = nil); merge!(DEFAULTS); super; end\n"
  tmp.class_eval methods
  CLASSES[name] = tmp

Public Instance Methods

event[key] → value click to toggle source

Returns the value stored with the key. This will return nil if key does not exist. key must be a Symbol or String object

static VALUE event_aref(VALUE self, VALUE key)
        char *attr = key2attr(key);
        struct lwes_event *e = lwesrb_get_event(self);
        struct lwes_event_attribute *eattr;

        eattr = lwes_hash_get(e->attributes, attr);
        return eattr ? lwesrb_attr_to_value(eattr) : Qnil;
event[key] = value click to toggle source

Assigns value to be stored in the event given by key. key must be a String or Symbol object.

static VALUE event_aset(VALUE self, VALUE key, VALUE val)
        char *attr = key2attr(key);
        LWES_BYTE attr_type = get_attr_type(self, attr);
        struct lwes_event *e = lwesrb_get_event(self);

        if (attr_type == LWES_STRING_TOKEN) {
                lwes_event_set_STRING(e, attr, StringValueCStr(val));
        } else if (attr_type == LWES_U_INT_16_TOKEN) {
                lwes_event_set_U_INT_16(e, attr, lwesrb_uint16(val));
        } else if (attr_type == LWES_INT_16_TOKEN) {
                lwes_event_set_INT_16(e, attr, lwesrb_int16(val));
        } else if (attr_type == LWES_U_INT_32_TOKEN) {
                lwes_event_set_U_INT_32(e, attr, lwesrb_uint32(val));
        } else if (attr_type == LWES_INT_32_TOKEN) {
                lwes_event_set_INT_32(e, attr, lwesrb_int32(val));
        } else if (attr_type == LWES_U_INT_64_TOKEN) {
                lwes_event_set_U_INT_64(e, attr, lwesrb_uint64(val));
        } else if (attr_type == LWES_INT_64_TOKEN) {
                lwes_event_set_INT_64(e, attr, lwesrb_int64(val));
        } else if (attr_type == LWES_IP_ADDR_TOKEN) {
                lwes_event_set_IP_ADDR(e, attr, lwesrb_ip_addr(val));
        } else if (attr_type == LWES_BOOLEAN_TOKEN) {
                lwes_event_set_BOOLEAN(e, attr, lwesrb_boolean(val));
        } else {
                         "unknown LWES attribute type: 0x%02x",
        return val;
initialize_copy(src) click to toggle source
Alias for: merge!
inspect() click to toggle source

returns a human-readable representation of the event

# File lib/lwes/event.rb, line 47
def inspect
  klass = self.class
  if LWES::Event == klass
merge(src) click to toggle source

duplicates the given event and overwrites the copy with values given in src

# File lib/lwes/event.rb, line 66
def merge src
  dup.merge! src
merge!(src) click to toggle source

overwrites the values of the existing event with those given in src

# File lib/lwes/event.rb, line 57
def merge! src
  src.to_hash.each { |k,v| self[k] = v }
Also aliased as: initialize_copy
to_hash → Hash click to toggle source

Returns an LWES::Event object as a plain Ruby hash. Useful for interoperating with existing Ruby code and also when you don’t have Event Specification Files finalized (or available).

static VALUE to_hash(VALUE self)
        struct lwes_event *e = lwesrb_get_event(self);
        VALUE rv = rb_hash_new();
        VALUE val;
        struct lwes_hash_enumeration hen;
        LWES_SHORT_STRING name;
        VALUE sym_attr_name;
        struct lwes_event_attribute *attr;

        if (e->eventName != NULL && CLASS_OF(self) == cLWES_Event) {
                val = rb_str_new2(e->eventName);
                rb_hash_aset(rv, sym_name, val);

        if (! lwes_hash_keys(e->attributes, &hen))
                return rv;
        while (lwes_hash_enumeration_has_more_elements(&hen)) {
                name = lwes_hash_enumeration_next_element(&hen);
                sym_attr_name = ID2SYM(rb_intern(name));
                attr = lwes_hash_get(e->attributes, name);
                if (attr == NULL)
                                 "missing attr during enumeration: %s", name);
                val = lwesrb_attr_to_value(attr);
                if (! NIL_P(val))
                        rb_hash_aset(rv, sym_attr_name, val);

        return rv;