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<HTML> <HEAD> <TITLE>Utility macros</TITLE>    </HEAD> <BODY> <H1>General Purpose Macros</H1> <PRE> /* ** (c) COPYRIGHT MIT 1995. ** Please first read the full copyright statement in the file COPYRIGH. */ </PRE> This module is a part of the <A HREF="http://www.w3.org/pub/WWW/Library/"> W3C Reference Library</A>. See also the system dependent file <A HREF="tcp.html">tcp module</A> for system specific information. <P> <PRE> #ifndef HTUTILS_H #define HTUTILS_H </PRE> <H2>Are we using Standard Code?</H2> We hopefully are... <PRE> #if defined(__STDC__) || defined(__cplusplus) || defined(WWW_MSWINDOWS) #define _STANDARD_CODE_ #endif </PRE> <H3>Variable Argument Functions</H3> This is normally one of the more tricky part in portable code as it very often doesn't work. If you are going to use it then watch out! <PRE> #ifdef _STANDARD_CODE_ #include <stdarg.h> #else #include <varargs.h> #endif </PRE> <A NAME="debug"><H2>Debug Message Control</H2></A> 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. <PRE> #ifndef DEBUG #define DEBUG /* No one ever turns this off as trace is too important */ #endif </PRE> <H3>Definition of the Global Trace Flag</H3> The global trace flag variable is available everywhere. <PRE> #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 */ </PRE> The <EM>WWWTRACE</EM> define outputs messages if verbose mode is active according to the following rules: <PRE> typedef enum _HTTraceFlags { SHOW_UTIL_TRACE = 0x1, /* 1 */ SHOW_APP_TRACE = 0x2, /* 10 */ SHOW_CACHE_TRACE = 0x4, /* 100 */ SHOW_SGML_TRACE = 0x8, /* 1000 */ SHOW_BIND_TRACE = 0x10, /* 1.0000 */ SHOW_THREAD_TRACE = 0x20, /* 10.0000 */ SHOW_STREAM_TRACE = 0x40, /* 100.0000 */ SHOW_PROTOCOL_TRACE = 0x80, /* 1000.0000 */ SHOW_MEM_TRACE = 0x100, /* 1.0000.0000 */ SHOW_URI_TRACE = 0x200, /* 10.0000.0000 */ SHOW_ANCHOR_TRACE = 0x800, /* 10.00.0000.0000 */ SHOW_ALL_TRACE = 0xFFF /* 11.11.1111.1111 */ } HTTraceFlags; </PRE> 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. <PRE> #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 ANCH_TRACE (WWWTRACE & SHOW_ANCHOR_TRACE) </PRE> <H3>Destination for Trace Messages</H3> 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 <PRE> 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, ...); </PRE> <H2>Standard C library for malloc() etc</H2> Replace memory allocation and free C RTL functions with VAXC$xxx_OPT alternatives for VAXC (but not DECC) on VMS. This makes a big performance difference. (Foteos Macrides). Also have a look at the <A HREF="HTMemory.html">Dynamic Memory Module</A> for how to handle <CODE>malloc</CODE> and <CODE>calloc</CODE>. <PRE> #ifdef vax #ifdef unix #define ultrix /* Assume vax+unix=ultrix */ #endif #endif #ifndef VMS #ifndef ultrix #ifdef NeXT #include <libc.h> /* NeXT */ #endif #ifndef Mips #ifndef MACH /* Vincent.Cate@furmint.nectar.cs.cmu.edu */ #include <stdlib.h> /* ANSI */ #endif #endif #else /* ultrix */ #include <malloc.h> #include <memory.h> #include <stdio.h> #include <stdlib.h> /* ANSI */ /* BSN */ #endif #else /* VMS */ #include <stdio.h> #include <stdlib.h> #include <unixlib.h> #include <ctype.h> #if defined(VAXC) && !defined(__DECC) #define malloc VAXC$MALLOC_OPT #define calloc VAXC$CALLOC_OPT #define free VAXC$FREE_OPT #define cfree VAXC$CFREE_OPT #define realloc VAXC$REALLOC_OPT #endif /* VAXC but not DECC */ #define unlink remove #define gmtime localtime #include <stat.h> #define S_ISDIR(m) (((m)&S_IFMT) == S_IFDIR) #define S_ISREG(m) (((m)&S_IFMT) == S_IFREG) #define putenv HTVMS_putenv #endif </PRE> <A NAME="declaration"><H2>Macros for Function Declarations</H2></A> <PRE> #define PUBLIC /* Accessible outside this module */ #define PRIVATE static /* Accessible only within this module */ #ifdef _STANDARD_CODE_ #if defined(sco) && !defined(_SCO_DS) #define CONST /* The pre SCO 5.0 CC compiler does not know const */ #else #define CONST const /* "const" only exists in STDC */ #endif #else #define CONST #endif /* _STANDARD_CODE_ (ANSI) */ </PRE> <H2>Booleans</H2> <PRE> #ifndef BOOLEAN_DEFINED typedef char BOOLEAN; /* Logical value */ #endif #ifndef CURSES #ifndef TRUE #define TRUE (BOOLEAN)1 #define FALSE (BOOLEAN)0 #endif #endif /* CURSES */ #ifndef BOOL #define BOOL BOOLEAN #endif #ifndef YES #define YES (BOOL)1 #define NO (BOOL)0 #endif </PRE> <H2>NULL Definition</H2> <PRE> #ifndef NULL #define NULL ((void *)0) #endif </PRE> <H2>Often used Interger Macros</H2> <H3>Min and Max functions</H3> <PRE> #ifndef HTMIN #define HTMIN(a,b) ((a) <= (b) ? (a) : (b)) #define HTMAX(a,b) ((a) >= (b) ? (a) : (b)) #endif </PRE> <H3>Double abs function</H3> <PRE> #ifndef HTDABS #define HTDABS(a) ((a) < 0.0 ? (-(a)) : (a)) #endif </PRE> <A NAME="ReturnCodes"><H2>Return Codes for Protocol Modules and Streams</H2></A> Theese are the codes returned from the protocol modules, and the stream modules. Success are (>=0) and failure are (<0) <PRE> #define HT_OK 0 /* Generic success */ #define HT_ALL 1 /* Used by Net Manager */ #define HT_CLOSED 29992 /* The socket was closed */ #define HT_PERSISTENT 29993 /* Wait for persistent connection */ #define HT_IGNORE 29994 /* Ignore this in the Net manager */ #define HT_NO_DATA 29995 /* OK but no data was loaded */ #define HT_RELOAD 29996 /* If we must reload the document */ #define HT_PERM_REDIRECT 29997 /* Redo the retrieve with a new URL */ #define HT_TEMP_REDIRECT 29998 /* Redo the retrieve with a new URL */ #define HT_LOADED 29999 /* Instead of a socket */ #define HT_ERROR -1 /* Generic failure */ #define HT_NO_ACCESS -10 /* Access not available */ #define HT_FORBIDDEN -11 /* Access forbidden */ #define HT_RETRY -13 /* If service isn't available */ #define HT_INTERNAL -100 /* Weird -- should never happen. */ #define HT_WOULD_BLOCK -29997 /* If we are in a select */ #define HT_INTERRUPTED -29998 /* Note the negative value! */ #define HT_PAUSE -29999 /* If we want to pause a stream */ </PRE> <H2>Upper- and Lowercase macros</H2> 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. <PRE> #include <ctype.h> #ifndef TOLOWER #define TOLOWER(c) tolower(c) #define TOUPPER(c) toupper(c) #endif </PRE> <H2>Max and Min values for Integers and Floating Point</H2> <PRE> #ifdef FLT_EPSILON /* The ANSI C way define */ #define HT_EPSILON FLT_EPSILON #else #define HT_EPSILON 0.00000001 #endif </PRE> <H2>White Characters</H2> Is character <B>c</B> white space? <PRE> #define WHITE(c) isspace(c) </PRE> <H2>The local equivalents of CR and LF</H2> 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. <PRE> #define LF FROMASCII('\012') /* ASCII line feed LOCAL EQUIVALENT */ #define CR FROMASCII('\015') /* Will be converted to ^M for transmission */ </PRE> <H2>Library Dynamic Memory Magement</H2> The Library has it's own dynamic memory API which is declared in <A HREF="HTMemory.html">memory management module</A>. <PRE> #include "HTMemory.h" </PRE> <PRE> #endif /* HT_UTILS.h */ </PRE> End of utility declarations </BODY> </HTML>