Implemented a nearly generic Queue in scriptland.

scripts/base/init-default.bro

@@ -12,6 +12,7 @@
 @load base/utils/numbers
 @load base/utils/paths
 @load base/utils/patterns
+@load base/utils/queue
 @load base/utils/strings
 @load base/utils/thresholds
 @load base/utils/urls

scripts/base/utils/queue.bro

@@ -0,0 +1,177 @@
+##! A FIFO string queue.
+
+module Queue;
+
+export {
+	## Settings for initializing the queue.
+	type Settings: record {
+		## If a maximum length is set for the queue
+		## it will maintain itself at that 
+		## maximum length automatically.
+		max_len: count &optional;
+	};
+
+	## The internal data structure for the queue.
+	type Queue: record {};
+
+	## Initialize a queue record structure.
+	## 
+	## s: A :bro:record:`Settings` record configuring the queue.
+	##
+	## Returns: An opaque queue record.
+	global init:       function(s: Settings): Queue;
+
+	## Push a string onto the top of a queue.
+	## 
+	## q: The queue to push the string into.
+	## 
+	## val: The string to push 
+	global push:       function(q: Queue, val: any);
+
+	## Pop a string from the bottom of a queue.
+	##
+	## q: The queue to pop the string from.
+	##
+	## Returns: The string popped from the queue.
+	global pop:        function(q: Queue): any;
+
+	## Merge two queue's together.  If any settings are applied 
+	## to the queues, the settings from q1 are used for the new
+	## merged queue.
+	## 
+	## q1: The first queue.  Settings are taken from here.
+	##
+	## q2: The second queue.
+	## 
+	## Returns: A new queue from merging the other two together.
+	global merge:      function(q1: Queue, q2: Queue): Queue;
+
+	## Get the number of items in a queue.
+	## 
+	## q: The queue.
+	##
+	## Returns: The length of the queue.
+	global len:     function(q: Queue): count;
+	
+	## Get the contents of the queue as a string vector.
+	## 
+	## q: The queue.
+	##
+	## Returns: A :bro:type:`vector of string` containing the 
+	##          current contents of q.
+	global get_str_vector: function(q: Queue): vector of string;
+
+	## Get the contents of the queue as a count vector.  Use care
+	## with this function.  If the data put into the queue wasn't 
+	## integers you will get conversion errors.
+	## 
+	## q: The queue.
+	##
+	## Returns: A :bro:type:`vector of count` containing the 
+	##          current contents of q.
+	global get_cnt_vector: function(q: Queue): vector of count;
+}
+
+redef record Queue += {
+	# Indicator for if the queue was appropriately initialized.
+	initialized: bool                   &default=F;
+	# The values are stored here.
+	vals:        table[count] of any &optional;
+	# Settings for the queue.
+	settings:    Settings               &optional;
+	# The top value in the vals table.
+	top:         count                  &default=0;
+	# The bottom value in the vals table.
+	bottom:      count                  &default=0;
+	# The number of bytes in the queue.
+	size:        count                  &default=0;
+};
+
+function init(s: Settings): Queue
+	{
+	local q: Queue;
+	q$vals=table();
+	q$settings = copy(s);
+	q$initialized=T;
+	return q;
+	}
+
+function push(q: Queue, val: any)
+	{
+	if ( q$settings?$max_len && len(q) >= q$settings$max_len )
+		pop(q);
+	q$vals[q$top] = val;
+	++q$top;
+	}
+
+function pop(q: Queue): any
+	{
+	local ret = q$vals[q$bottom];
+	delete q$vals[q$bottom];
+	++q$bottom;
+	return ret;
+	}
+
+function merge(q1: Queue, q2: Queue): Queue
+	{
+	local ret = init(q1$settings);
+	local i = q1$bottom;
+	local j = q2$bottom;
+	for ( ignored_val in q1$vals )
+		{
+		if ( i in q1$vals )
+			push(ret, q1$vals[i]);
+		if ( j in q2$vals )
+			push(ret, q2$vals[j]);
+		++i;
+		++j;
+		}
+	}
+
+function len(q: Queue): count
+	{
+	return |q$vals|;
+	}
+
+function get_str_vector(q: Queue): vector of string
+	{
+	local ret: vector of string;
+	local i = q$bottom;
+	local j = 0;
+	# Really dumb hack, this is only to provide
+	# the iteration for the correct number of 
+	# values in q$vals.
+	for ( ignored_val in q$vals )
+		{
+		if ( i >= q$top )
+			break;
+
+		ret[j] = cat(q$vals[i]);
+		++j; ++i;
+		}
+	return ret;
+	}
+
+function get_cnt_vector(q: Queue): vector of count
+	{
+	local ret: vector of count;
+	local i = q$bottom;
+	local j = 0;
+	# Really dumb hack, this is only to provide
+	# the iteration for the correct number of 
+	# values in q$vals.
+	for ( ignored_val in q$vals )
+		{
+		if ( i >= q$top )
+			break;
+
+		# TODO: this is terrible and should be replaced by 
+		#       a more generic version of the various 
+		#       functions to get vectors of values.
+		#       (the way "any" works right now makes this impossible though)
+		ret[j] = to_count(cat(q$vals[i]));
+		++j; ++i;
+		}
+	return ret;
+	}
+

testing/btest/Baseline/scripts.base.utils.queue/output

@@ -0,0 +1,11 @@
+This is a get_cnt_vector test: 3
+This is a get_cnt_vector test: 4
+This is a get_str_vector test: 3
+This is a get_str_vector test: 4
+Testing pop: 3
+Length after pop: 1
+Size of q2: 4
+String queue value: test 1
+String queue value: test 2
+String queue value: test 2
+String queue value: test 1

testing/btest/scripts/base/utils/queue.test

@@ -0,0 +1,35 @@
+# @TEST-EXEC: bro -b %INPUT > output
+# @TEST-EXEC: btest-diff output
+
+# This is loaded by default
+@load base/utils/queue
+
+event bro_init()
+	{
+	local q = Queue::init([$max_len=2]);
+	Queue::push(q, 1);
+	Queue::push(q, 2);
+	Queue::push(q, 3);
+	Queue::push(q, 4);
+	local test1 =  Queue::get_cnt_vector(q);
+	for ( i in test1 )
+		print fmt("This is a get_cnt_vector test: %d", test1[i]);
+
+	local test2 =  Queue::get_str_vector(q);
+	for ( i in test2 )
+		print fmt("This is a get_str_vector test: %s", test2[i]);
+
+	local test_val = Queue::pop(q);
+	print fmt("Testing pop: %s", test_val);
+	print fmt("Length after pop: %d", Queue::len(q));
+
+	local q2 = Queue::init([]);
+	Queue::push(q2, "test 1");
+	Queue::push(q2, "test 2");
+	Queue::push(q2, "test 2");
+	Queue::push(q2, "test 1");
+	print fmt("Size of q2: %d", Queue::len(q2));
+	local test3: vector of string = Queue::get_str_vector(q2);
+	for ( i in test3 )
+		print fmt("String queue value: %s", test3[i]);
+	}