# General Purpose Macros

    /*
    **	(c) COPYRIGHT MIT 1995.
    **	Please first read the full copyright statement in the file COPYRIGH.
    */

This module is a part of the W3C Sample Code Library. See also the system dependent file sysdep module for system specific information.

    #ifndef HTUTILS_H
    #define HTUTILS_H

## Debug Message Control

This is the global flag for setting the `WWWTRACE` options. The verbose mode is no longer a simple boolean but a bit field so that it is possible to see parts of the output messages.

    #ifndef DEBUG
    #define DEBUG	/* No one ever turns this off as trace is too important */
    extern void HTDebugBreak(void);
    #endif

### Definition of the Global Trace Flag

The global trace flag variable is available everywhere.

    #ifdef DEBUG
    #ifdef WWW_WIN_DLL
    extern int *		WWW_TraceFlag;	 /* In DLLs, we need the indirection */
    #define WWWTRACE	(*WWW_TraceFlag)
    #else
    extern int		WWW_TraceFlag;	     /* Global flag for all W3 trace */
    #define WWWTRACE	(WWW_TraceFlag)
    #endif /* WWW_WIN_DLL */
    #else
    #define WWWTRACE	0
    #endif /* DEBUG */

The `WWWTRACE` define outputs messages if verbose mode is active according to the following rules:

    typedef enum _HTTraceFlags {
        SHOW_UTIL_TRACE	= 0x1,
        SHOW_APP_TRACE	= 0x2,
        SHOW_CACHE_TRACE	= 0x4,
        SHOW_SGML_TRACE	= 0x8,
        SHOW_BIND_TRACE	= 0x10,
        SHOW_THREAD_TRACE	= 0x20,
        SHOW_STREAM_TRACE	= 0x40,
        SHOW_PROTOCOL_TRACE = 0x80,
        SHOW_MEM_TRACE	= 0x100,
        SHOW_URI_TRACE	= 0x200,
        SHOW_AUTH_TRACE	= 0x400,
        SHOW_ANCHOR_TRACE	= 0x800,
        SHOW_PICS_TRACE	= 0x1000,
        SHOW_CORE_TRACE	= 0x2000,
        SHOW_MUX_TRACE      = 0x4000,
        SHOW_ALL_TRACE	= 0xFFFFFFFF
    } HTTraceFlags;

The flags are made so that they can serve as a group flag for correlated trace messages, e.g. showing messages for SGML and HTML at the same time.

    #define UTIL_TRACE	(WWWTRACE & SHOW_UTIL_TRACE)
    #define APP_TRACE	(WWWTRACE & SHOW_APP_TRACE)
    #define CACHE_TRACE	(WWWTRACE & SHOW_CACHE_TRACE)
    #define SGML_TRACE	(WWWTRACE & SHOW_SGML_TRACE)
    #define BIND_TRACE	(WWWTRACE & SHOW_BIND_TRACE)
    #define THD_TRACE	(WWWTRACE & SHOW_THREAD_TRACE)
    #define STREAM_TRACE	(WWWTRACE & SHOW_STREAM_TRACE)
    #define PROT_TRACE	(WWWTRACE & SHOW_PROTOCOL_TRACE)
    #define MEM_TRACE	(WWWTRACE & SHOW_MEM_TRACE)
    #define URI_TRACE	(WWWTRACE & SHOW_URI_TRACE)
    #define AUTH_TRACE	(WWWTRACE & SHOW_AUTH_TRACE)
    #define ANCH_TRACE	(WWWTRACE & SHOW_ANCHOR_TRACE)
    #define PICS_TRACE	(WWWTRACE & SHOW_PICS_TRACE)
    #define CORE_TRACE	(WWWTRACE & SHOW_CORE_TRACE)
    #define MUX_TRACE	(WWWTRACE & SHOW_MUX_TRACE)

### Destination for Trace Messages

You can send trace messages to various destinations depending on the type of your application. By default, on Unix the messages are sent to stderr using fprintf() and if we are on Windows and have a windows applications then register a HTTraceCallback function. This is done with HTTrace_setCallback. It tells HTTrace to call a HTTraceCallback. If your compiler has problems with va_list, then you may forget about registering the callback and instead macro HTTrace as follows: #define HTTrace MyAppSpecificTrace

    typedef int HTTraceCallback(const char * fmt, va_list pArgs);

    extern void HTTrace_setCallback(HTTraceCallback * pCall);
    extern HTTraceCallback * HTTrace_getCallback(void);

    extern int HTTrace(const char * fmt, ...);

### Trace Data Logging

A similare mechanism exists for logging data, except that is adds a data and length argument to the trace call.

    typedef int HTTraceDataCallback(char * data, size_t len,
    				char * fmt, va_list pArgs);

    extern void HTTraceData_setCallback(HTTraceDataCallback * pCall);
    extern HTTraceDataCallback * HTTraceData_getCallback(void);

    extern int HTTraceData(char * data, size_t len, char * fmt, ...);

### Hiding Extraneous Logging Messages

Many of the long logging strings are wrapped with the HTHIDE macro. This is usually defined to pass its parameter to the loggin functions. However, if your application doesn't use the logging, you may define HTHIDE to pass only a 0 to eliminate the strings from the executable image.

    #define HTHIDE(A)	A

## Macros for Function Declarations

    #define PUBLIC			/* Accessible outside this module     */
    #define PRIVATE static		/* Accessible only within this module */

## Often used Interger Macros

### Min and Max functions

    #ifndef HTMIN
    #define HTMIN(a,b) ((a) <= (b) ? (a) : (b))
    #define HTMAX(a,b) ((a) >= (b) ? (a) : (b))
    #endif

### Double abs function

    #ifndef HTDABS
    #define HTDABS(a) ((a) < 0.0 ? (-(a)) : (a))
    #endif

## Return Codes for Protocol Modules and Streams

Theese are the codes returned from the protocol modules, and the stream modules. Success are (>=0) and failure are (<0)

    #define HT_OK			0	/* Generic success */
    #define HT_ALL			1	/* Used by Net Manager */

    #define HT_CONTINUE             100     /* Continue an operation */
    #define HT_UPGRADE              101     /* Switching protocols */

    #define HT_LOADED		200  	/* Everything's OK */
    #define HT_CREATED  	        201     /* New object is created */
    #define HT_ACCEPTED  	        202     /* Accepted */
    #define HT_NO_DATA		204  	/* OK but no data was loaded */
    #define HT_RESET_CONTENT        205     /* Reset content */
    #define HT_PARTIAL_CONTENT	206  	/* Partial Content */

    #define HT_MULTIPLE_CHOICES     300     /* Multiple choices */
    #define HT_PERM_REDIRECT	301  	/* Permanent redirection */
    #define HT_TEMP_REDIRECT	302  	/* Temporary redirection */
    #define HT_SEE_OTHER            303     /* See other */
    #define HT_NOT_MODIFIED         304     /* Not Modified */
    #define HT_USE_PROXY            305     /* Use Proxy */

    #define HT_IGNORE		900  	/* Ignore this in the Net manager */
    #define HT_CLOSED		901  	/* The socket was closed */
    #define HT_PENDING		902  	/* Wait for connection */
    #define HT_RELOAD		903  	/* If we must reload the document */

    #define HT_ERROR		-1	/* Generic failure */

    #define HT_NO_ACCESS		-401	/* Unauthorized */
    #define HT_FORBIDDEN		-403	/* Access forbidden */
    #define HT_NOT_ACCEPTABLE	-406	/* Not Acceptable */
    #define HT_NO_PROXY_ACCESS      -407    /* Proxy Authentication Failed */
    #define HT_CONFLICT             -409    /* Conflict */
    #define HT_LENGTH_REQUIRED      -411    /* Length required */

    #define HT_RETRY		-503	/* If service isn't available */
    #define HT_BAD_VERSION		-505	/* Bad protocol version */

    #define HT_INTERNAL		-900    /* Weird -- should never happen. */
    #define HT_WOULD_BLOCK		-901    /* If we are in a select */
    #define HT_INTERRUPTED 		-902    /* Note the negative value! */
    #define HT_PAUSE                -903    /* If we want to pause a stream */
    #define HT_RECOVER_PIPE         -904    /* Recover pipe line */

## Upper- and Lowercase macros

The problem here is that toupper(x) is not defined officially unless isupper(x) is. These macros are CERTAINLY needed on #if defined(pyr) || define(mips) or BDSI platforms. For safefy, we make them mandatory.

    #ifndef TOLOWER
    #define TOLOWER(c) tolower(c)
    #define TOUPPER(c) toupper(c)
    #endif

## Max and Min values for Integers and Floating Point

    #ifdef FLT_EPSILON				    /* The ANSI C way define */
    #define HT_EPSILON FLT_EPSILON
    #else
    #define HT_EPSILON 0.00000001
    #endif

## White Characters

Is character c white space?

    #define WHITE(c) isspace(c)

## The local equivalents of CR and LF

We can check for these after net ascii text has been converted to the local representation. Similarly, we include them in strings to be sent as net ascii after translation.

    #define LF   FROMASCII('\012')  /* ASCII line feed LOCAL EQUIVALENT */
    #define CR   FROMASCII('\015')  /* Will be converted to ^M for transmission */

## Library Dynamic Memory Magement

The Library has it's own dynamic memory API which is declared in memory management module.

    #include "HTMemory.h"

    #endif /* HT_UTILS.h */