--- parser3/src/include/pa_pool.h 2001/01/26 15:28:39 1.2 +++ parser3/src/include/pa_pool.h 2001/03/22 16:38:19 1.41 @@ -1,14 +1,11 @@ -/* +/** @file + Parser: pool class decl. - String Chunk0 - ====== ======== - head--------->[ptr, size] - append_here-------->[ptr, size] - link_row ........ - . . - . [ptr, size] - ...........>[link to the next chunk] + Copyright (c) 2001 ArtLebedev Group (http://www.artlebedev.com) + Author: Alexander Petrosyan (http://design.ru/paf) + + $Id: pa_pool.h,v 1.41 2001/03/22 16:38:19 paf Exp $ */ #ifndef PA_POOL_H @@ -16,83 +13,189 @@ #include -class Pool; +class Exception; +class Temp_exception; + +/** + Pool mechanizm allows users not to free up allocated memory, + leaving that problem to 'pools'. + + Also holds Exception object, which can be temporary set using + Temp_exception auto-object. + + @see Pooled +*/ -class String { +class Pool { + friend Temp_exception; public: - enum { - CR_PREALLOCATED_COUNT=5, - CR_GROW_PERCENT=60 - }; + + Pool() : fstorage(0), fcontext(0), ftag(0), fexception(0) {} + ~Pool(); + + void set_storage(void *astorage) { fstorage=astorage; } + void set_context(void *acontext) { fcontext=acontext; } + void set_tag(void *atag) { ftag=atag; } + + void *storage() { return fstorage; } + void *context() { return fcontext; } + void *tag() { return ftag; } + + /// current exception object of the pool + Exception& exception() const { return *fexception; } + + /// allocates some bytes on pool + void *malloc(size_t size) { + return check(real_malloc(size), size); + } + /// allocates some bytes clearing them with zeros + void *calloc(size_t size) { + return check(real_calloc(size), size); + } private: - friend Pool; - // the pool I'm allocated on - Pool *pool; + void *fstorage; + void *fcontext; + void *ftag; - // 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; - } - 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; - - // new&constructors made private to enforce factory manufacturing at pool - void *operator new(size_t size, Pool *apool); - - void construct(Pool *apool); - String(Pool *apool) { - construct(apool); - } - String(Pool *apool, char *src) { - construct(apool); - *this+=src; +private: // implementation defined + + void *real_malloc(size_t size); + void *real_calloc(size_t size); + +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; - bool chunk_is_full() { - return append_here == link_row; +private: // exception handling + + // exception replacement mechanism is 'protected' from direct usage + // Temp_exception 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: + + // current request's exception object + Exception *fexception; - size_t size(); - char *c_str(); - String& operator += (char *src); +private: //disabled + + // Pool(const Pool&) {} + Pool& operator = (const Pool&) { return *this; } }; -class Pool { +/** + Base for all classes that are allocated in 'pools'. + + Holds Pool object. Contains useful wrappers to it's methods. + + @see NEW, Temp_exception +*/ +class Pooled { + // the pool i'm allocated on + Pool& fpool; public: - Pool(); - ~Pool(); - void *alloc(size_t size); - void *calloc(size_t size); - String *makeString() { - return new(this) String(this); + /// the Pooled-sole: Pooled instances can be allocated in Pool rather then on heap + static void *operator new(size_t size, Pool& apool) { + return apool.malloc(size); } - String *makeString(char *src) { - return new(this) String(this, src); + + Pooled(Pool& apool) : fpool(apool) { } + + /// my pool + Pool& pool() const { return fpool; } + + /// useful wrapper around pool + void *malloc(size_t size) const { return fpool.malloc(size); } + /// useful wrapper around pool + void *calloc(size_t size) const { return fpool.calloc(size); } + /// useful wrapper around pool + Exception& exception() const { return fpool.exception(); } }; +/// useful macro for creating objects on current Pooled object Pooled::pool() +#define NEW new(pool()) + +/** + Auto-object used for temporary changing Pool's exception(). + + Use by with these macros: + @code + TRY { + // ... + if(?) + THROW(?); + // ... + } CATCH(e) { + // code, using e fields + // e.comment() + } + END_CATCH + @endcode + + @see TRY, THROW +*/ +class Temp_exception { + Pool& fpool; + Exception *saved_exception; +public: + Temp_exception(Pool& apool, Exception& exception) : + fpool(apool), + saved_exception(apool.set_exception(&exception)) { + } + ~Temp_exception() { + fpool.restore_exception(saved_exception); + } +}; + +#define XTRY(pool) \ + { \ + Exception temp_exception; \ + Temp_exception le(pool, temp_exception); \ + if(setjmp(temp_exception.mark)==0) + +#define XTHROW(exception) exception._throw +#define XCATCH(e) \ + else{ \ + Exception& e=temp_exception; + +#define XEND_CATCH \ + } \ + } + +//@{ +/// @see Temp_exception +#define TRY XTRY(pool()) +#define THROW XTHROW(exception()) +#define CATCH(e) XCATCH(e) +#define END_CATCH XEND_CATCH + +#define PTRY XTRY(pool) +#define PTHROW XTHROW(pool.exception()) +#define PCATCH(e) XCATCH(e) +#define PEND_CATCH XEND_CATCH + +#define RTHROW XTHROW(r.pool().exception()) +//@} #endif