firebird-mirror/src/common/fb_exception.cpp

#include "firebird.h"

//#include "fb_exception.h"

#include <string.h>
#include <errno.h>
#include <stdarg.h>
#include "gen/iberror.h"
#include "../common/classes/alloc.h"

namespace {

// This logic taken from JRD is bad, bad, bad!
// Replace it with attachment-level buffers whenever possible
const size_t ENGINE_FAILURE_SPACE = 4096;

typedef Firebird::CircularStringsBuffer<ENGINE_FAILURE_SPACE> CircularBuffer;

class InterlockedStringsBuffer : public CircularBuffer {
public:
	virtual char* alloc(const char* string, size_t length) 
	{
		buffer_lock.enter();
		char* new_string = CircularBuffer::alloc(string, length);
		buffer_lock.leave();
		return new_string;
	}
private:
	Firebird::Mutex buffer_lock;
};

ISC_STATUS dupStringTemp(const char* s)
{
	const size_t len = strlen(s);
	char *string = FB_NEW(*getDefaultMemoryPool()) char[len + 1];
	memcpy(string, s, len + 1);
	return (ISC_STATUS)(IPTR)(string);
}

void fill_status(ISC_STATUS *ptr, ISC_STATUS status, va_list status_args)
{
	// Move in status and clone transient strings
	*ptr++ = isc_arg_gds;
	*ptr++ = status;
	while (true) 
	{
		const ISC_STATUS type = *ptr++ = va_arg(status_args, ISC_STATUS);
		if (type == isc_arg_end) 
			break;

		switch (type) {
		case isc_arg_cstring: 
			{				
				const size_t len = *ptr++ = va_arg(status_args, ISC_STATUS);
				char *string = FB_NEW(*getDefaultMemoryPool()) char[len];
				const char *temp = reinterpret_cast<char*>(va_arg(status_args, ISC_STATUS));
				memcpy(string, temp, len);
				*ptr++ = (ISC_STATUS)(IPTR)(string);
				break;
			}
		case isc_arg_string:
		case isc_arg_interpreted:
			{
				*ptr++ = dupStringTemp(reinterpret_cast<char*>(va_arg(status_args, ISC_STATUS)));
				break;
			}
		default:
			*ptr++ = va_arg(status_args, ISC_STATUS);
			break;
		}
	}	
}

} // namespace

namespace Firebird {

/********************************* status_exception *******************************/

status_exception::status_exception() throw() : 
	m_strings_permanent(true)
{
	memset(m_status_vector, 0, sizeof(m_status_vector));
}

status_exception::status_exception(const ISC_STATUS *status_vector, bool permanent) throw() : 
	m_strings_permanent(permanent)
{
	ISC_STATUS *ptr = m_status_vector;
	while (true) 
	{
		const ISC_STATUS type = *ptr++ = *status_vector++;
		if (type == isc_arg_end)
			break;
		if (type == isc_arg_cstring)
			*ptr++ = *status_vector++;
		*ptr++ = *status_vector++;
	}
}
	
void status_exception::set_status(const ISC_STATUS *new_vector, bool permanent) throw()
{
	release_vector();
	m_strings_permanent = permanent;
	fb_assert(new_vector != 0);
	memcpy(m_status_vector, new_vector, sizeof(m_status_vector));
}

void status_exception::release_vector() throw()
{
	if (m_strings_permanent)
		return;
	
	// Free owned strings
	ISC_STATUS *ptr = m_status_vector;
	 while (true) 
	 {
		const ISC_STATUS type = *ptr++;
		if (type == isc_arg_end)
			break;

		switch (type) {
		case isc_arg_cstring:
			ptr++;
			delete[] reinterpret_cast<char*>(*ptr++);
			break;
		case isc_arg_string:
		case isc_arg_interpreted:
			delete[] reinterpret_cast<char*>(*ptr++);
			break;
		default:
			ptr++;
			break;
		}		
	}
}

status_exception::~status_exception() throw() 
{
	release_vector();
}

void fatal_exception::raiseFmt(const char* format, ...) 
{
	va_list args;
	va_start(args, format);
	char buffer[1024];
	VSNPRINTF(buffer, sizeof(buffer), format, args);
	buffer[sizeof(buffer) - 1] = 0;
	va_end(args);
	throw fatal_exception(buffer);
}

void status_exception::raise(const ISC_STATUS *status_vector) 
{
	throw status_exception(status_vector, true);
}
	
void status_exception::raise(ISC_STATUS status, ...) 
{
	va_list args;
	va_start(args, status);
	ISC_STATUS_ARRAY temp;
	fill_status(temp, status, args);
	va_end(args);
	throw status_exception(temp, false);
}

/********************************* BadAlloc ****************************/

void BadAlloc::raise()
{
	throw BadAlloc();
}

/********************************* LongJump ****************************/

void LongJump::raise()
{
	throw LongJump();
}

/********************************* system_call_failed ****************************/

system_call_failed::system_call_failed(const char* v_syscall, int v_error_code) : 
	status_exception(0, false), errorCode(v_error_code)
{
	ISC_STATUS temp[] = {isc_arg_gds, 
						isc_sys_request, 
						isc_arg_string, dupStringTemp(v_syscall), 
						SYS_ARG, errorCode, 
						isc_arg_end};
	set_status(temp, false);
}

void system_call_failed::raise(const char* syscall, int error_code)
{
	throw system_call_failed(syscall, error_code);
}

void system_call_failed::raise(const char* syscall)
{
#ifdef WIN_NT
	int error_code = GetLastError();
#else
	int error_code = errno;
#endif
	throw system_call_failed(syscall, error_code);
}

/********************************* fatal_exception ********************************/

fatal_exception::fatal_exception(const char* message) :
	status_exception(0, false)
{
	ISC_STATUS temp[] = {isc_arg_gds, 
						isc_random, 
						isc_arg_string, dupStringTemp(message), 
						isc_arg_end};
	set_status(temp, false);
}

// Moved to the header due to gpre. Gpre non-static can't receive it, but we
// want to avoid problems with picky compilers that can't find what().
// We can't link this file into normal gpre.
// Keep in sync with the constructor above, please; "message" becomes 4th element
// after initialization of status vector.
//const char* fatal_exception::what() const throw()
//{
//	return reinterpret_cast<const char*>(value()[3]);
//}

void fatal_exception::raise(const char* message)
{
	throw fatal_exception(message);
}

/************************** exception handling routines ***************************/

static InterlockedStringsBuffer engine_failures;

ISC_STATUS stuff_exception(ISC_STATUS* const status_vector, const Exception& ex, StringsBuffer *sb) throw() 
{
	// Note that this function will call unexpected() that will terminate process 
	// if exception appears during status vector serialization

	if (!sb)
		sb = &engine_failures;
	
	ISC_STATUS *sv = status_vector;

	switch (ex.kind())
	{
	case Exception::ExMemory:
		*sv++ = isc_arg_gds;
		*sv++ = isc_virmemexh;
		*sv++ = isc_arg_end;
		break;

	case Exception::ExStatus:
		{
			const status_exception* c_ex = reinterpret_cast<const status_exception*>(&ex);
			const ISC_STATUS *ptr = c_ex->value();
			if (c_ex->strings_permanent()) 
			{
				// Copy status vector
				 while (true) 
				 {
					const ISC_STATUS type = *sv++ = *ptr++;
					if (type == isc_arg_end)
						break;
					if (type == isc_arg_cstring)
						*sv++ = *ptr++;
					*sv++ = *ptr++;
				}
			}
			else {
				// Move in status and clone transient strings
				 while (true) 
				 {
					const ISC_STATUS type = *sv++ = *ptr++;
					if (type == isc_arg_end)
						break;

					switch (type) {
					case isc_arg_cstring: 
						{				
							const UCHAR len = *sv++ = *ptr++;
							char *temp = reinterpret_cast<char*>(*ptr++);
							*sv++ = (ISC_STATUS)(IPTR) (sb->alloc(temp, len));
							break;
						}
					case isc_arg_string:
					case isc_arg_interpreted:
						{
							char *temp = reinterpret_cast<char*>(*ptr++);
							*sv++ = (ISC_STATUS)(IPTR) (sb->alloc(temp, strlen(temp)));
							break;
						}
					default:
						*sv++ = *ptr++;
						break;
					}
				}
			}
		}
		break;
		
	case Exception::ExJump:
		break;	// keep SV 'as is'
	
	default:
		{
			char temp[256];
			SNPRINTF(temp, sizeof(temp) - 1,
				"Unexpected Firebird::Exception (kind=%d what()=\"%s\")",
				ex.kind(), ex.what());
			temp[sizeof(temp) - 1] = 0;
			*sv++ = isc_arg_gds;
			*sv++ = isc_random;
			*sv++ = isc_arg_string;
			*sv++ = (ISC_STATUS)(IPTR) (sb->alloc(temp, strlen(temp)));
			*sv++ = isc_arg_end;
		}
		break;
	} 
	
	return status_vector[1];
}


const char* status_string(const char* string) 
{
	return status_nstring(string, strlen(string));
}

const char* status_nstring(const char* string, size_t length) 
{
	return engine_failures.alloc(string, length);
}

}	// namespace Firebird