freebsd-nq/contrib/tcl/generic/tclStringObj.c
1997-10-01 13:19:13 +00:00

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/*
* tclStringObj.c --
*
* This file contains procedures that implement string operations
* on Tcl objects. To do this efficiently (i.e. to allow many
* appends to be done to an object without constantly reallocating
* the space for the string representation) we overallocate the
* space for the string and use the internal representation to keep
* track of the extra space. Objects with this internal
* representation are called "expandable string objects".
*
* Copyright (c) 1995-1997 Sun Microsystems, Inc.
*
* See the file "license.terms" for information on usage and redistribution
* of this file, and for a DISCLAIMER OF ALL WARRANTIES.
*
* SCCS: @(#) tclStringObj.c 1.30 97/07/24 18:53:30
*/
#include "tclInt.h"
/*
* Prototypes for procedures defined later in this file:
*/
static void ConvertToStringType _ANSI_ARGS_((Tcl_Obj *objPtr));
static void DupStringInternalRep _ANSI_ARGS_((Tcl_Obj *objPtr,
Tcl_Obj *copyPtr));
static int SetStringFromAny _ANSI_ARGS_((Tcl_Interp *interp,
Tcl_Obj *objPtr));
static void UpdateStringOfString _ANSI_ARGS_((Tcl_Obj *objPtr));
/*
* The structure below defines the string Tcl object type by means of
* procedures that can be invoked by generic object code.
*/
Tcl_ObjType tclStringType = {
"string", /* name */
(Tcl_FreeInternalRepProc *) NULL, /* freeIntRepProc */
DupStringInternalRep, /* dupIntRepProc */
UpdateStringOfString, /* updateStringProc */
SetStringFromAny /* setFromAnyProc */
};
/*
*----------------------------------------------------------------------
*
* Tcl_NewStringObj --
*
* This procedure is normally called when not debugging: i.e., when
* TCL_MEM_DEBUG is not defined. It creates a new string object and
* initializes it from the byte pointer and length arguments.
*
* When TCL_MEM_DEBUG is defined, this procedure just returns the
* result of calling the debugging version Tcl_DbNewStringObj.
*
* Results:
* A newly created string object is returned that has ref count zero.
*
* Side effects:
* The new object's internal string representation will be set to a
* copy of the length bytes starting at "bytes". If "length" is
* negative, use bytes up to the first NULL byte; i.e., assume "bytes"
* points to a C-style NULL-terminated string. The object's type is set
* to NULL. An extra NULL is added to the end of the new object's byte
* array.
*
*----------------------------------------------------------------------
*/
#ifdef TCL_MEM_DEBUG
#undef Tcl_NewStringObj
Tcl_Obj *
Tcl_NewStringObj(bytes, length)
register char *bytes; /* Points to the first of the length bytes
* used to initialize the new object. */
register int length; /* The number of bytes to copy from "bytes"
* when initializing the new object. If
* negative, use bytes up to the first
* NULL byte. */
{
return Tcl_DbNewStringObj(bytes, length, "unknown", 0);
}
#else /* if not TCL_MEM_DEBUG */
Tcl_Obj *
Tcl_NewStringObj(bytes, length)
register char *bytes; /* Points to the first of the length bytes
* used to initialize the new object. */
register int length; /* The number of bytes to copy from "bytes"
* when initializing the new object. If
* negative, use bytes up to the first
* NULL byte. */
{
register Tcl_Obj *objPtr;
if (length < 0) {
length = bytes ? strlen(bytes) : 0 ;
}
TclNewObj(objPtr);
TclInitStringRep(objPtr, bytes, length);
return objPtr;
}
#endif /* TCL_MEM_DEBUG */
/*
*----------------------------------------------------------------------
*
* Tcl_DbNewStringObj --
*
* This procedure is normally called when debugging: i.e., when
* TCL_MEM_DEBUG is defined. It creates new string objects. It is the
* same as the Tcl_NewStringObj procedure above except that it calls
* Tcl_DbCkalloc directly with the file name and line number from its
* caller. This simplifies debugging since then the checkmem command
* will report the correct file name and line number when reporting
* objects that haven't been freed.
*
* When TCL_MEM_DEBUG is not defined, this procedure just returns the
* result of calling Tcl_NewStringObj.
*
* Results:
* A newly created string object is returned that has ref count zero.
*
* Side effects:
* The new object's internal string representation will be set to a
* copy of the length bytes starting at "bytes". If "length" is
* negative, use bytes up to the first NULL byte; i.e., assume "bytes"
* points to a C-style NULL-terminated string. The object's type is set
* to NULL. An extra NULL is added to the end of the new object's byte
* array.
*
*----------------------------------------------------------------------
*/
#ifdef TCL_MEM_DEBUG
Tcl_Obj *
Tcl_DbNewStringObj(bytes, length, file, line)
register char *bytes; /* Points to the first of the length bytes
* used to initialize the new object. */
register int length; /* The number of bytes to copy from "bytes"
* when initializing the new object. If
* negative, use bytes up to the first
* NULL byte. */
char *file; /* The name of the source file calling this
* procedure; used for debugging. */
int line; /* Line number in the source file; used
* for debugging. */
{
register Tcl_Obj *objPtr;
if (length < 0) {
length = strlen(bytes);
}
TclDbNewObj(objPtr, file, line);
TclInitStringRep(objPtr, bytes, length);
return objPtr;
}
#else /* if not TCL_MEM_DEBUG */
Tcl_Obj *
Tcl_DbNewStringObj(bytes, length, file, line)
register char *bytes; /* Points to the first of the length bytes
* used to initialize the new object. */
register int length; /* The number of bytes to copy from "bytes"
* when initializing the new object. If
* negative, use bytes up to the first
* NULL byte. */
char *file; /* The name of the source file calling this
* procedure; used for debugging. */
int line; /* Line number in the source file; used
* for debugging. */
{
return Tcl_NewStringObj(bytes, length);
}
#endif /* TCL_MEM_DEBUG */
/*
*----------------------------------------------------------------------
*
* Tcl_SetStringObj --
*
* Modify an object to hold a string that is a copy of the bytes
* indicated by the byte pointer and length arguments.
*
* Results:
* None.
*
* Side effects:
* The object's string representation will be set to a copy of
* the "length" bytes starting at "bytes". If "length" is negative, use
* bytes up to the first NULL byte; i.e., assume "bytes" points to a
* C-style NULL-terminated string. The object's old string and internal
* representations are freed and the object's type is set NULL.
*
*----------------------------------------------------------------------
*/
void
Tcl_SetStringObj(objPtr, bytes, length)
register Tcl_Obj *objPtr; /* Object whose internal rep to init. */
char *bytes; /* Points to the first of the length bytes
* used to initialize the object. */
register int length; /* The number of bytes to copy from "bytes"
* when initializing the object. If
* negative, use bytes up to the first
* NULL byte.*/
{
register Tcl_ObjType *oldTypePtr = objPtr->typePtr;
/*
* Free any old string rep, then set the string rep to a copy of
* the length bytes starting at "bytes".
*/
if (Tcl_IsShared(objPtr)) {
panic("Tcl_SetStringObj called with shared object");
}
Tcl_InvalidateStringRep(objPtr);
if (length < 0) {
length = strlen(bytes);
}
TclInitStringRep(objPtr, bytes, length);
/*
* Set the type to NULL and free any internal rep for the old type.
*/
if ((oldTypePtr != NULL) && (oldTypePtr->freeIntRepProc != NULL)) {
oldTypePtr->freeIntRepProc(objPtr);
}
objPtr->typePtr = NULL;
}
/*
*----------------------------------------------------------------------
*
* Tcl_SetObjLength --
*
* This procedure changes the length of the string representation
* of an object.
*
* Results:
* None.
*
* Side effects:
* If the size of objPtr's string representation is greater than
* length, then it is reduced to length and a new terminating null
* byte is stored in the strength. If the length of the string
* representation is greater than length, the storage space is
* reallocated to the given length; a null byte is stored at the
* end, but other bytes past the end of the original string
* representation are undefined. The object's internal
* representation is changed to "expendable string".
*
*----------------------------------------------------------------------
*/
void
Tcl_SetObjLength(objPtr, length)
register Tcl_Obj *objPtr; /* Pointer to object. This object must
* not currently be shared. */
register int length; /* Number of bytes desired for string
* representation of object, not including
* terminating null byte. */
{
char *new;
if (Tcl_IsShared(objPtr)) {
panic("Tcl_SetObjLength called with shared object");
}
if (objPtr->typePtr != &tclStringType) {
ConvertToStringType(objPtr);
}
if ((long)length > objPtr->internalRep.longValue) {
/*
* Not enough space in current string. Reallocate the string
* space and free the old string.
*/
new = (char *) ckalloc((unsigned) (length+1));
if (objPtr->bytes != NULL) {
memcpy((VOID *) new, (VOID *) objPtr->bytes,
(size_t) objPtr->length);
Tcl_InvalidateStringRep(objPtr);
}
objPtr->bytes = new;
objPtr->internalRep.longValue = (long) length;
}
objPtr->length = length;
if ((objPtr->bytes != NULL) && (objPtr->bytes != tclEmptyStringRep)) {
objPtr->bytes[length] = 0;
}
}
/*
*----------------------------------------------------------------------
*
* Tcl_AppendToObj --
*
* This procedure appends a sequence of bytes to an object.
*
* Results:
* None.
*
* Side effects:
* The bytes at *bytes are appended to the string representation
* of objPtr.
*
*----------------------------------------------------------------------
*/
void
Tcl_AppendToObj(objPtr, bytes, length)
register Tcl_Obj *objPtr; /* Points to the object to append to. */
char *bytes; /* Points to the bytes to append to the
* object. */
register int length; /* The number of bytes to append from
* "bytes". If < 0, then append all bytes
* up to NULL byte. */
{
int newLength, oldLength;
if (Tcl_IsShared(objPtr)) {
panic("Tcl_AppendToObj called with shared object");
}
if (objPtr->typePtr != &tclStringType) {
ConvertToStringType(objPtr);
}
if (length < 0) {
length = strlen(bytes);
}
if (length == 0) {
return;
}
oldLength = objPtr->length;
newLength = length + oldLength;
if ((long)newLength > objPtr->internalRep.longValue) {
/*
* There isn't currently enough space in the string
* representation so allocate additional space. In fact,
* overallocate so that there is room for future growth without
* having to reallocate again.
*/
Tcl_SetObjLength(objPtr, 2*newLength);
}
if (length > 0) {
memcpy((VOID *) (objPtr->bytes + oldLength), (VOID *) bytes,
(size_t) length);
objPtr->length = newLength;
objPtr->bytes[objPtr->length] = 0;
}
}
/*
*----------------------------------------------------------------------
*
* 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)
{
va_list argList;
register Tcl_Obj *objPtr;
int newLength, oldLength;
register char *string, *dst;
objPtr = (Tcl_Obj *) TCL_VARARGS_START(Tcl_Obj *,arg1,argList);
if (Tcl_IsShared(objPtr)) {
panic("Tcl_AppendStringsToObj called with shared object");
}
if (objPtr->typePtr != &tclStringType) {
ConvertToStringType(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.
*/
newLength = oldLength = objPtr->length;
while (1) {
string = va_arg(argList, char *);
if (string == NULL) {
break;
}
newLength += strlen(string);
}
if (newLength == oldLength) {
return;
}
if ((long)newLength > objPtr->internalRep.longValue) {
/*
* 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 overallocate the space so
* that we won't have to do as much reallocation in the future.
*/
Tcl_SetObjLength(objPtr,
(objPtr->length == 0) ? newLength : 2*newLength);
}
/*
* Make a second pass through the arguments, appending all the
* strings to the object.
*/
TCL_VARARGS_START(Tcl_Obj *,arg1,argList);
dst = objPtr->bytes + oldLength;
while (1) {
string = va_arg(argList, char *);
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 = newLength;
va_end(argList);
}
/*
*----------------------------------------------------------------------
*
* ConvertToStringType --
*
* This procedure converts the internal representation of an object
* to "expandable string" type.
*
* Results:
* None.
*
* Side effects:
* Any old internal reputation for objPtr is freed and the
* internal representation is set to that for an expandable string
* (the field internalRep.longValue holds 1 less than the allocated
* length of objPtr's string representation).
*
*----------------------------------------------------------------------
*/
static void
ConvertToStringType(objPtr)
register Tcl_Obj *objPtr; /* Pointer to object. Must have a
* typePtr that isn't &tclStringType. */
{
if (objPtr->typePtr != NULL) {
if (objPtr->bytes == NULL) {
objPtr->typePtr->updateStringProc(objPtr);
}
if (objPtr->typePtr->freeIntRepProc != NULL) {
objPtr->typePtr->freeIntRepProc(objPtr);
}
}
objPtr->typePtr = &tclStringType;
if (objPtr->bytes != NULL) {
objPtr->internalRep.longValue = (long)objPtr->length;
} else {
objPtr->internalRep.longValue = 0;
objPtr->length = 0;
}
}
/*
*----------------------------------------------------------------------
*
* 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 representation of type
* "expandable string". */
register Tcl_Obj *copyPtr; /* Object with internal rep to set. Must
* not currently have an internal rep.*/
{
/*
* 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.
*/
copyPtr->internalRep.longValue = (long)copyPtr->length;
copyPtr->typePtr = &tclStringType;
}
/*
*----------------------------------------------------------------------
*
* SetStringFromAny --
*
* Create an internal representation of type "expandable string"
* for an object.
*
* Results:
* This operation always succeeds and returns TCL_OK.
*
* Side effects:
* This procedure does nothing; there is no advantage in converting
* the internal representation now, so we just defer it.
*
*----------------------------------------------------------------------
*/
static int
SetStringFromAny(interp, objPtr)
Tcl_Interp *interp; /* Used for error reporting if not NULL. */
Tcl_Obj *objPtr; /* The object to convert. */
{
return TCL_OK;
}
/*
*----------------------------------------------------------------------
*
* UpdateStringOfString --
*
* Update the string representation for an object whose internal
* representation is "expandable string".
*
* Results:
* None.
*
* Side effects:
* None.
*
*----------------------------------------------------------------------
*/
static void
UpdateStringOfString(objPtr)
Tcl_Obj *objPtr; /* Object with string rep to update. */
{
/*
* The string is almost always valid already, in which case there's
* nothing for us to do. The only case we have to worry about is if
* the object is totally null. In this case, set the string rep to
* an empty string.
*/
if (objPtr->bytes == NULL) {
objPtr->bytes = tclEmptyStringRep;
objPtr->length = 0;
}
return;
}