--- parser3/src/include/pa_pool.h	2001/01/26 15:28:39	1.2
+++ parser3/src/include/pa_pool.h	2001/03/10 15:44:30	1.26
@@ -1,14 +1,5 @@
 /*
-
-	String				Chunk0
-	======				========
-	head--------->[ptr, size]
-	append_here-------->[ptr, size]
-	link_row      ........
-			.			.
-			.			[ptr, size]
-			...........>[link to the next chunk]
-
+  $Id: pa_pool.h,v 1.26 2001/03/10 15:44:30 paf Exp $
 */
 
 #ifndef PA_POOL_H
@@ -16,83 +7,119 @@
 
 #include <stddef.h>
 
-class Pool;
+//class String;
+class Exception;
+class Temp_exception;
 
-class String {
+class Pool {
+	friend Temp_exception;
 public:
-	enum {
-		CR_PREALLOCATED_COUNT=5,
-		CR_GROW_PERCENT=60
-	};
 
-private:
-	friend Pool;
+	Pool() : fexception(0) {}
+	~Pool() {}
 
-	// the pool I'm allocated on
-	Pool *pool;
+	Exception& exception() const { return *fexception; }
 
-	// last chank allocated count cache
-	int curr_chunk_rows;
-	struct Chunk {
-		// the number of rows per chunk
-		int count;
-		union Row {
-			// chunk item
-			struct {
-				char *ptr;  // pointer to the start of string fragment
-				size_t size;  // length of the fragment
-			} item;
-			Chunk *link;  // link to the next chunk in chain
-		} first[CR_PREALLOCATED_COUNT];
-		// next rows are here
-		Chunk *preallocated_link;
+	void *malloc(size_t size) {
+		return check(real_malloc(size), size);
+	}
+	void *calloc(size_t size) {
+		return check(real_calloc(size), size);
 	}
-		head;  // the head chunk of the chunk chain
 
-	// next append would write to this record
-	Chunk::Row *append_here;
-	
-	// the address of place where lies address 
-	// of the link to the next chunk to allocate
-	Chunk::Row *link_row;
+private: // implementation defined
 
-	// new&constructors made private to enforce factory manufacturing at pool
-	void *operator new(size_t size, Pool *apool);
+    void *real_malloc(size_t size);
+    void *real_calloc(size_t size);
 
-	void construct(Pool *apool);
-	String(Pool *apool) { 
-		construct(apool); 
-	}
-	String(Pool *apool, char *src) {
-		construct(apool);
-		*this+=src;
+private: 
+
+	// checks whether mem allocated OK. throws exception otherwise
+	void *check(void *ptr, size_t size) {
+		if(ptr)
+			return ptr;
+
+		fail(size);
+
+		// never reached
+		return 0;
 	}
+	// throws proper exception
+	void fail(size_t size) const;
+
+protected: // exception handling
 
-	bool chunk_is_full() {
-		return append_here == link_row;
+	// exception replacement mechanism is 'protected' from direct usage
+	// Temp_exception_change object enforces paired set/restore
+	Exception *set_exception(Exception *e){
+		Exception *r=fexception;
+		fexception=e;
+		return r;
+	}
+	void restore_exception(Exception *e) {
+		fexception=e;
 	}
-	void expand();
 
-public:
+private:
 
-	size_t size();
-	char *c_str();
-	String& operator += (char *src);
+	// current request's exception object
+	Exception *fexception;
+
+private: //disabled
+
+	// Pool(const Pool&) {}
+	Pool& operator = (const Pool&) { return *this; }
 };
 
-class Pool {
+class Pooled {
+	// the pool i'm allocated on
+	Pool& fpool;
 public:
-	Pool();
-	~Pool();
-    void *alloc(size_t size);
-    void *calloc(size_t size);
+	
+	static void *operator new(size_t size, Pool& apool) { 
+		return apool.malloc(size);
+	}
+
+	Pooled(Pool& apool) : fpool(apool) {
+	}
 
-	String *makeString() { 
-		return new(this) String(this);
+	Pool& pool() const { return fpool; }
+
+	void *malloc(size_t size) const { return fpool.malloc(size); }
+	void *calloc(size_t size) const { return fpool.calloc(size); }
+	Exception& exception() const { return fpool.exception(); }
+};
+#define NEW new(pool())
+
+class Temp_exception {
+	Pool pool;
+	Exception *saved_exception;
+public:
+	Temp_exception(Pool& apool, Exception& exception) : 
+		pool(apool),
+		saved_exception(apool.set_exception(&exception)) {
 	}
-	String *makeString(char *src) {
-		return new(this) String(this, src);
+	~Temp_exception() { 
+		pool.restore_exception(saved_exception); 
 	}
 };
 
+#define TRY \
+	{ \
+		Exception temp_exception; \
+		Temp_exception le(pool(), temp_exception); \
+		if(setjmp(temp_exception.mark)==0)
+
+#define THROW exception()._throw
+#define POOL_THROW pool.exception()._throw
+#define CATCH(e) \
+		else{ \
+			Exception& e=temp_exception;
+
+#define END_CATCH \
+		} \
+	}
+// usage:
+//   TRY { ...; if(?) RAISE(?); ...; } CATCH(e) { catch-code e.comment() } END_CATCH
+
 #endif