tclstringobj.c

来自「tcl是工具命令语言」· C语言 代码 · 共 1,878 行 · 第 1/4 页

    stringPtr->hasUnicode = 0;
    
    memcpy((VOID *) (objPtr->bytes + oldLength), (VOID *) bytes,
	    (size_t) numBytes);
    objPtr->bytes[newLength] = 0;
    objPtr->length = newLength;
}

/*
 *----------------------------------------------------------------------
 *
 * Tcl_AppendStringsToObjVA --
 *
 *	This procedure appends one or more null-terminated strings
 *	to an object.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	The contents of all the string arguments are appended to the
 *	string representation of objPtr.
 *
 *----------------------------------------------------------------------
 */

void
Tcl_AppendStringsToObjVA (objPtr, argList)
    Tcl_Obj *objPtr;		/* Points to the object to append to. */
    va_list argList;		/* Variable argument list. */
{
#define STATIC_LIST_SIZE 16
    String *stringPtr;
    int newLength, oldLength, attemptLength;
    register char *string, *dst;
    char *static_list[STATIC_LIST_SIZE];
    char **args = static_list;
    int nargs_space = STATIC_LIST_SIZE;
    int nargs, i;

    if (Tcl_IsShared(objPtr)) {
	panic("Tcl_AppendStringsToObj called with shared object");
    }

    SetStringFromAny(NULL, objPtr);

    /*
     * Figure out how much space is needed for all the strings, and
     * expand the string representation if it isn't big enough. If no
     * bytes would be appended, just return.  Note that on some platforms
     * (notably OS/390) the argList is an array so we need to use memcpy.
     */

    nargs = 0;
    newLength = 0;
    oldLength = objPtr->length;
    while (1) {
	string = va_arg(argList, char *);
	if (string == NULL) {
	    break;
	}
 	if (nargs >= nargs_space) {
 	    /* 
 	     * Expand the args buffer
 	     */
 	    nargs_space += STATIC_LIST_SIZE;
 	    if (args == static_list) {
 	    	args = (void *)ckalloc(nargs_space * sizeof(char *));
 		for (i = 0; i < nargs; ++i) {
 		    args[i] = static_list[i];
 		}
 	    } else {
 		args = (void *)ckrealloc((void *)args,
			nargs_space * sizeof(char *));
 	    }
 	}
	newLength += strlen(string);
	args[nargs++] = string;
    }
    if (newLength == 0) {
	goto done;
    }

    stringPtr = GET_STRING(objPtr);
    if (oldLength + newLength > (int) stringPtr->allocated) {

	/*
	 * There isn't currently enough space in the string
	 * representation, so allocate additional space.  If the current
	 * string representation isn't empty (i.e. it looks like we're
	 * doing a series of appends) then try to allocate extra space to
	 * accomodate future growth: first try to double the required memory;
	 * if that fails, try a more modest allocation.  See the "TCL STRING
	 * GROWTH ALGORITHM" comment at the top of this file for an explanation
	 * of this growth algorithm.  Otherwise, if the current string
	 * representation is empty, exactly enough memory is allocated.
	 */

	if (oldLength == 0) {
	    Tcl_SetObjLength(objPtr, newLength);
	} else {
	    attemptLength = 2 * (oldLength + newLength);
	    if (Tcl_AttemptSetObjLength(objPtr, attemptLength) == 0) {
		attemptLength = oldLength + (2 * newLength) +
		    TCL_GROWTH_MIN_ALLOC;
		Tcl_SetObjLength(objPtr, attemptLength);
	    }
	}
    }

    /*
     * Make a second pass through the arguments, appending all the
     * strings to the object.
     */

    dst = objPtr->bytes + oldLength;
    for (i = 0; i < nargs; ++i) {
 	string = args[i];
	if (string == NULL) {
	    break;
	}
	while (*string != 0) {
	    *dst = *string;
	    dst++;
	    string++;
	}
    }

    /*
     * Add a null byte to terminate the string.  However, be careful:
     * it's possible that the object is totally empty (if it was empty
     * originally and there was nothing to append).  In this case dst is
     * NULL; just leave everything alone.
     */

    if (dst != NULL) {
	*dst = 0;
    }
    objPtr->length = oldLength + newLength;

    done:
    /*
     * If we had to allocate a buffer from the heap, 
     * free it now.
     */
 
    if (args != static_list) {
     	ckfree((void *)args);
    }
#undef STATIC_LIST_SIZE
}

/*
 *----------------------------------------------------------------------
 *
 * Tcl_AppendStringsToObj --
 *
 *	This procedure appends one or more null-terminated strings
 *	to an object.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	The contents of all the string arguments are appended to the
 *	string representation of objPtr.
 *
 *----------------------------------------------------------------------
 */

void
Tcl_AppendStringsToObj TCL_VARARGS_DEF(Tcl_Obj *,arg1)
{
    register Tcl_Obj *objPtr;
    va_list argList;

    objPtr = TCL_VARARGS_START(Tcl_Obj *,arg1,argList);
    Tcl_AppendStringsToObjVA(objPtr, argList);
    va_end(argList);
}

/*
 *---------------------------------------------------------------------------
 *
 * FillUnicodeRep --
 *
 *	Populate the Unicode internal rep with the Unicode form of its string
 *	rep.  The object must alread have a "String" internal rep.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	Reallocates the String internal rep.
 *
 *---------------------------------------------------------------------------
 */

static void
FillUnicodeRep(objPtr)
    Tcl_Obj *objPtr;	/* The object in which to fill the unicode rep. */
{
    String *stringPtr;
    size_t uallocated;
    char *src, *srcEnd;
    Tcl_UniChar *dst;
    src = objPtr->bytes;
    
    stringPtr = GET_STRING(objPtr);
    if (stringPtr->numChars == -1) {
	stringPtr->numChars = Tcl_NumUtfChars(src, objPtr->length);
    }
    stringPtr->hasUnicode = (stringPtr->numChars > 0);

    uallocated = STRING_UALLOC(stringPtr->numChars);
    if (uallocated > stringPtr->uallocated) {
    
	/*
	 * If not enough space has been allocated for the unicode rep,
	 * reallocate the internal rep object.
	 */

	/*
	 * There isn't currently enough space in the Unicode
	 * representation so allocate additional space.  If the current
	 * Unicode representation isn't empty (i.e. it looks like we've
	 * done some appends) then overallocate the space so
	 * that we won't have to do as much reallocation in the future.
	 */

	if (stringPtr->uallocated > 0) {
	    uallocated *= 2;
	}
	stringPtr = (String *) ckrealloc((char*) stringPtr,
		STRING_SIZE(uallocated));
	stringPtr->uallocated = uallocated;
    }

    /*
     * Convert src to Unicode and store the coverted data in "unicode".
     */
    
    srcEnd = src + objPtr->length;
    for (dst = stringPtr->unicode; src < srcEnd; dst++) {
	src += TclUtfToUniChar(src, dst);
    }
    *dst = 0;
    
    SET_STRING(objPtr, stringPtr);
}

/*
 *----------------------------------------------------------------------
 *
 * DupStringInternalRep --
 *
 *	Initialize the internal representation of a new Tcl_Obj to a
 *	copy of the internal representation of an existing string object.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	copyPtr's internal rep is set to a copy of srcPtr's internal
 *	representation.
 *
 *----------------------------------------------------------------------
 */

static void
DupStringInternalRep(srcPtr, copyPtr)
    register Tcl_Obj *srcPtr;	/* Object with internal rep to copy.  Must
				 * have an internal rep of type "String". */
    register Tcl_Obj *copyPtr;	/* Object with internal rep to set.  Must
				 * not currently have an internal rep.*/
{
    String *srcStringPtr = GET_STRING(srcPtr);
    String *copyStringPtr = NULL;

    /*
     * If the src obj is a string of 1-byte Utf chars, then copy the
     * string rep of the source object and create an "empty" Unicode
     * internal rep for the new object.  Otherwise, copy Unicode
     * internal rep, and invalidate the string rep of the new object.
     */
    
    if (srcStringPtr->hasUnicode == 0) {
    	copyStringPtr = (String *) ckalloc(STRING_SIZE(STRING_UALLOC(0)));
	copyStringPtr->uallocated = STRING_UALLOC(0);
    } else {
	copyStringPtr = (String *) ckalloc(
	    STRING_SIZE(srcStringPtr->uallocated));
	copyStringPtr->uallocated = srcStringPtr->uallocated;

	memcpy((VOID *) copyStringPtr->unicode,
		(VOID *) srcStringPtr->unicode,
		(size_t) srcStringPtr->numChars * sizeof(Tcl_UniChar));
	copyStringPtr->unicode[srcStringPtr->numChars] = 0;
    }
    copyStringPtr->numChars = srcStringPtr->numChars;
    copyStringPtr->hasUnicode = srcStringPtr->hasUnicode;
    copyStringPtr->allocated = srcStringPtr->allocated;

    /*
     * Tricky point: the string value was copied by generic object
     * management code, so it doesn't contain any extra bytes that
     * might exist in the source object.
     */

    copyStringPtr->allocated = copyPtr->length;

    SET_STRING(copyPtr, copyStringPtr);
    copyPtr->typePtr = &tclStringType;
}

/*
 *----------------------------------------------------------------------
 *
 * SetStringFromAny --
 *
 *	Create an internal representation of type "String" for an object.
 *
 * Results:
 *	This operation always succeeds and returns TCL_OK.
 *
 * Side effects:
 *	Any old internal reputation for objPtr is freed and the
 *	internal representation is set to "String".
 *
 *----------------------------------------------------------------------
 */

static int
SetStringFromAny(interp, objPtr)
    Tcl_Interp *interp;		/* Used for error reporting if not NULL. */
    register Tcl_Obj *objPtr;	/* The object to convert. */
{
    /*
     * The Unicode object is optimized for the case where each UTF char
     * in a string is only one byte.  In this case, we store the value of
     * numChars, but we don't copy the bytes to the unicodeObj->unicode.
     */

    if (objPtr->typePtr != &tclStringType) {
	String *stringPtr;

	if (objPtr->typePtr != NULL) {
	    if (objPtr->bytes == NULL) {
		objPtr->typePtr->updateStringProc(objPtr);
	    }
	    if ((objPtr->typePtr->freeIntRepProc) != NULL) {
		(*objPtr->typePtr->freeIntRepProc)(objPtr);
	    }
	}
	objPtr->typePtr = &tclStringType;

	/*
	 * Allocate enough space for the basic String structure.
	 */

	stringPtr = (String *) ckalloc(STRING_SIZE(STRING_UALLOC(0)));
	stringPtr->numChars = -1;
	stringPtr->uallocated = STRING_UALLOC(0);
	stringPtr->hasUnicode = 0;

	if (objPtr->bytes != NULL) {
	    stringPtr->allocated = objPtr->length;	    
 	    objPtr->bytes[objPtr->length] = 0;
	} else {
	    objPtr->length = 0;
	}
	SET_STRING(objPtr, stringPtr);
    }
    return TCL_OK;
}

/*
 *----------------------------------------------------------------------
 *
 * UpdateStringOfString --
 *
 *	Update the string representation for an object whose internal
 *	representation is "String".
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	The object's string may be set by converting its Unicode
 *	represention to UTF format.
 *
 *----------------------------------------------------------------------
 */

static void
UpdateStringOfString(objPtr)
    Tcl_Obj *objPtr;		/* Object with string rep to update. */
{
    int i, size;
    Tcl_UniChar *unicode;
    char dummy[TCL_UTF_MAX];
    char *dst;
    String *stringPtr;

    stringPtr = GET_STRING(objPtr);
    if ((objPtr->bytes == NULL) || (stringPtr->allocated == 0)) {

	if (stringPtr->numChars <= 0) {

	    /*
	     * If there is no Unicode rep, or the string has 0 chars,
	     * then set the string rep to an empty string.
	     */

	    objPtr->bytes = tclEmptyStringRep;
	    objPtr->length = 0;
	    return;
	}

	unicode = stringPtr->unicode;

	/*
	 * Translate the Unicode string to UTF.  "size" will hold the
	 * amount of space the UTF string needs.
	 */

	size = 0;
	for (i = 0; i < stringPtr->numChars; i++) {
	    size += Tcl_UniCharToUtf((int) unicode[i], dummy);
	}
	
	dst = (char *) ckalloc((unsigned) (size + 1));
	objPtr->bytes = dst;
	objPtr->length = size;
	stringPtr->allocated = size;

	for (i = 0; i < stringPtr->numChars; i++) {
	    dst += Tcl_UniCharToUtf(unicode[i], dst);
	}
	*dst = '\0';
    }
    return;
}

/*
 *----------------------------------------------------------------------
 *
 * FreeStringInternalRep --
 *
 *	Deallocate the storage associated with a String data object's
 *	internal representation.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	Frees memory. 
 *
 *----------------------------------------------------------------------
 */

static void
FreeStringInternalRep(objPtr)
    Tcl_Obj *objPtr;		/* Object with internal rep to free. */
{
    ckfree((char *) GET_STRING(objPtr));
}