binpac: Adding a new binpac::init() function that must be called by the host

before anything else.

Internally, this function compiles all regular expressions, avoiding
to that inside the regexp constructore. The code is a bit hackish due
to the way the regexp code depends on the Bro header.

tools/binpac/lib/CMakeLists.txt

@@ -22,6 +22,7 @@ set(binpac_headers
 set(binpac_lib_SRCS
     binpac_buffer.cc
     binpac_bytestring.cc
+    binpac_regex.cc
     ${binpac_headers}
 )
 

tools/binpac/lib/binpac_regex.cc

@@ -0,0 +1,10 @@
+
+#include <vector>
+
+class RE_Matcher;
+
+namespace binpac {
+
+std::vector<RE_Matcher*>* uncompiled_re_matchers = 0;
+
+}

tools/binpac/lib/binpac_regex.h

@@ -9,12 +9,19 @@ class RE_Matcher;
 namespace binpac
 {
 
+// Internal vector recording not yet compiled matchers.
+extern std::vector<RE_Matcher*>* uncompiled_re_matchers;
+
 class RegExMatcher {
 public:
 	RegExMatcher(const char *pattern)
 		: pattern_(pattern)
 		{
-		re_matcher_ = 0;
+		if ( ! uncompiled_re_matchers )
+			uncompiled_re_matchers = new std::vector<RE_Matcher*>;
+
+		re_matcher_ = new RE_Matcher(pattern_.c_str());
+		uncompiled_re_matchers->push_back(re_matcher_);
 		}
 
 	~RegExMatcher()
@@ -25,19 +32,45 @@ public:
 	// Returns the length of longest match, or -1 on mismatch.
 	int MatchPrefix(const_byteptr data, int len)
 		{
-		if ( ! re_matcher_ )
-			{
-			re_matcher_ = new RE_Matcher(pattern_.c_str());
-			re_matcher_->Compile();
-			}
 		return re_matcher_->MatchPrefix(data, len);
 		}
 
 private:
+	friend void ::binpac::init();
+
+	// Function, and state, for compiling matchers.
+	static void init();
+
 	string pattern_;
 	RE_Matcher *re_matcher_;
 };
 
+inline void RegExMatcher::init()
+	{
+	if ( ! uncompiled_re_matchers )
+		return;
+
+	for ( size_t i = 0; i < uncompiled_re_matchers->size(); ++i )
+		{
+		if ( ! (*uncompiled_re_matchers)[i]->Compile() )
+			{
+			fprintf(stderr, "binpac: cannot compile regular expression\n");
+			exit(1);
+			}
+		}
+
+	uncompiled_re_matchers->clear();
+	}
+
+// Must be called before any binpac functionality is used.
+//
+// Note, this must be defined here, and inline, because the RE functionality
+// can only be used when compiling from inside Bro.
+inline void init()
+	{
+	RegExMatcher::init();
+	}
+
 }  // namespace binpac
 
 #endif  // binpac_regex_h