scuffed-code/icu4c/source/i18n/rbt_set.cpp
George Rhoten 4a15917960 ICU-1962 Don't do malloc(0), which returns NULL on some platforms.
new[0] will always return a pointer.

X-SVN-Rev: 9229
2002-07-17 16:58:32 +00:00

448 lines
15 KiB
C++

/*
**********************************************************************
* Copyright (C) 1999, International Business Machines
* Corporation and others. All Rights Reserved.
**********************************************************************
* Date Name Description
* 11/17/99 aliu Creation.
**********************************************************************
*/
#include "unicode/unistr.h"
#include "unicode/uniset.h"
#include "rbt_set.h"
#include "rbt_rule.h"
#include "cmemory.h"
U_CDECL_BEGIN
static void U_EXPORT2 U_CALLCONV _deleteRule(void *rule) {
delete (U_NAMESPACE_QUALIFIER TransliterationRule *)rule;
}
U_CDECL_END
//----------------------------------------------------------------------
// BEGIN Debugging support
//----------------------------------------------------------------------
// #define DEBUG_RBT
#ifdef DEBUG_RBT
#include <stdio.h>
#include "charstr.h"
/**
* @param appendTo result is appended to this param.
* @param input the string being transliterated
* @param pos the index struct
*/
static UnicodeString& _formatInput(UnicodeString &appendTo,
const UnicodeString& input,
const UTransPosition& pos) {
// Output a string of the form aaa{bbb|ccc|ddd}eee, where
// the {} indicate the context start and limit, and the ||
// indicate the start and limit.
if (0 <= pos.contextStart &&
pos.contextStart <= pos.start &&
pos.start <= pos.limit &&
pos.limit <= pos.contextLimit &&
pos.contextLimit <= input.length()) {
UnicodeString a, b, c, d, e;
input.extractBetween(0, pos.contextStart, a);
input.extractBetween(pos.contextStart, pos.start, b);
input.extractBetween(pos.start, pos.limit, c);
input.extractBetween(pos.limit, pos.contextLimit, d);
input.extractBetween(pos.contextLimit, input.length(), e);
appendTo.append(a).append((UChar)123/*{*/).append(b).
append((UChar)124/*|*/).append(c).append((UChar)124/*|*/).append(d).
append((UChar)125/*}*/).append(e);
} else {
appendTo.append("INVALID UTransPosition");
//appendTo.append((UnicodeString)"INVALID UTransPosition {cs=" +
// pos.contextStart + ", s=" + pos.start + ", l=" +
// pos.limit + ", cl=" + pos.contextLimit + "} on " +
// input);
}
return appendTo;
}
// Append a hex string to the target
UnicodeString& _appendHex(uint32_t number,
int32_t digits,
UnicodeString& target) {
static const UChar digitString[] = {
0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39,
0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0
};
while (digits--) {
target += digitString[(number >> (digits*4)) & 0xF];
}
return target;
}
// Replace nonprintable characters with unicode escapes
UnicodeString& _escape(const UnicodeString &source,
UnicodeString &target) {
for (int32_t i = 0; i < source.length(); ) {
UChar32 ch = source.char32At(i);
i += UTF_CHAR_LENGTH(ch);
if (ch < 0x09 || (ch > 0x0A && ch < 0x20)|| ch > 0x7E) {
if (ch <= 0xFFFF) {
target += "\\u";
_appendHex(ch, 4, target);
} else {
target += "\\U";
_appendHex(ch, 8, target);
}
} else {
target += ch;
}
}
return target;
}
#endif
inline void _debugOut(const char* msg, TransliterationRule* rule,
const Replaceable& theText, UTransPosition& pos) {
#ifdef DEBUG_RBT
UnicodeString buf(msg, "");
if (rule) {
UnicodeString r;
rule->toRule(r, TRUE);
buf.append((UChar)32).append(r);
}
buf.append(UnicodeString(" => ", ""));
UnicodeString* text = (UnicodeString*)&theText;
_formatInput(buf, *text, pos);
UnicodeString esc;
_escape(buf, esc);
CharString cbuf(esc);
printf("%s\n", (char*) cbuf);
#endif
}
//----------------------------------------------------------------------
// END Debugging support
//----------------------------------------------------------------------
// Fill the precontext and postcontext with the patterns of the rules
// that are masking one another.
static void maskingError(const U_NAMESPACE_QUALIFIER TransliterationRule& rule1,
const U_NAMESPACE_QUALIFIER TransliterationRule& rule2,
UParseError& parseError) {
U_NAMESPACE_QUALIFIER UnicodeString r;
int32_t len;
parseError.line = parseError.offset = -1;
// for pre-context
rule1.toRule(r, FALSE);
len = uprv_min(r.length(), U_PARSE_CONTEXT_LEN-1);
r.extract(0, len, parseError.preContext);
parseError.preContext[len] = 0;
//for post-context
r.truncate(0);
rule2.toRule(r, FALSE);
len = uprv_min(r.length(), U_PARSE_CONTEXT_LEN-1);
r.extract(0, len, parseError.postContext);
parseError.postContext[len] = 0;
}
U_NAMESPACE_BEGIN
const char TransliterationRuleSet::fgClassID=0;
/**
* Construct a new empty rule set.
*/
TransliterationRuleSet::TransliterationRuleSet(UErrorCode& status) : UObject() {
ruleVector = new UVector(&_deleteRule, NULL, status);
rules = NULL;
maxContextLength = 0;
if (ruleVector == NULL) {
status = U_MEMORY_ALLOCATION_ERROR;
}
}
/**
* Copy constructor.
*/
TransliterationRuleSet::TransliterationRuleSet(const TransliterationRuleSet& other) :
UObject(other),
ruleVector(0),
rules(0),
maxContextLength(other.maxContextLength) {
int32_t i, len;
uprv_memcpy(index, other.index, sizeof(index));
UErrorCode status = U_ZERO_ERROR;
ruleVector = new UVector(&_deleteRule, NULL, status);
if (other.ruleVector != 0 && ruleVector != 0 && U_SUCCESS(status)) {
len = other.ruleVector->size();
for (i=0; i<len && U_SUCCESS(status); ++i) {
ruleVector->addElement(new TransliterationRule(
*(TransliterationRule*)other.ruleVector->elementAt(i)), status);
}
}
if (other.rules != 0) {
UParseError p;
freeze(p, status);
}
}
/**
* Destructor.
*/
TransliterationRuleSet::~TransliterationRuleSet() {
delete ruleVector; // This deletes the contained rules
uprv_free(rules);
}
void TransliterationRuleSet::setData(const TransliterationRuleData* d) {
/**
* We assume that the ruleset has already been frozen.
*/
int32_t len = index[256]; // see freeze()
for (int32_t i=0; i<len; ++i) {
rules[i]->setData(d);
}
}
/**
* Return the maximum context length.
* @return the length of the longest preceding context.
*/
int32_t TransliterationRuleSet::getMaximumContextLength(void) const {
return maxContextLength;
}
/**
* Add a rule to this set. Rules are added in order, and order is
* significant. The last call to this method must be followed by
* a call to <code>freeze()</code> before the rule set is used.
*
* <p>If freeze() has already been called, calling addRule()
* unfreezes the rules, and freeze() must be called again.
*
* @param adoptedRule the rule to add
*/
void TransliterationRuleSet::addRule(TransliterationRule* adoptedRule,
UErrorCode& status) {
if (U_FAILURE(status)) {
delete adoptedRule;
return;
}
ruleVector->addElement(adoptedRule, status);
int32_t len;
if ((len = adoptedRule->getContextLength()) > maxContextLength) {
maxContextLength = len;
}
uprv_free(rules);
rules = 0;
}
/**
* Check this for masked rules and index it to optimize performance.
* The sequence of operations is: (1) add rules to a set using
* <code>addRule()</code>; (2) freeze the set using
* <code>freeze()</code>; (3) use the rule set. If
* <code>addRule()</code> is called after calling this method, it
* invalidates this object, and this method must be called again.
* That is, <code>freeze()</code> may be called multiple times,
* although for optimal performance it shouldn't be.
*/
void TransliterationRuleSet::freeze(UParseError& parseError,UErrorCode& status) {
/* Construct the rule array and index table. We reorder the
* rules by sorting them into 256 bins. Each bin contains all
* rules matching the index value for that bin. A rule
* matches an index value if string whose first key character
* has a low byte equal to the index value can match the rule.
*
* Each bin contains zero or more rules, in the same order
* they were found originally. However, the total rules in
* the bins may exceed the number in the original vector,
* since rules that have a variable as their first key
* character will generally fall into more than one bin.
*
* That is, each bin contains all rules that either have that
* first index value as their first key character, or have
* a set containing the index value as their first character.
*/
int32_t n = ruleVector->size();
int32_t j;
int16_t x;
UVector v(2*n, status); // heuristic; adjust as needed
if (U_FAILURE(status)) {
return;
}
/* Precompute the index values. This saves a LOT of time.
* Be careful not to call malloc(0).
*/
int16_t* indexValue = (int16_t*) uprv_malloc( sizeof(int16_t) * (n > 0 ? n : 1) );
/* test for NULL */
if (indexValue == 0) {
status = U_MEMORY_ALLOCATION_ERROR;
return;
}
for (j=0; j<n; ++j) {
TransliterationRule* r = (TransliterationRule*) ruleVector->elementAt(j);
indexValue[j] = r->getIndexValue();
}
for (x=0; x<256; ++x) {
index[x] = v.size();
for (j=0; j<n; ++j) {
if (indexValue[j] >= 0) {
if (indexValue[j] == x) {
v.addElement(ruleVector->elementAt(j), status);
}
} else {
// If the indexValue is < 0, then the first key character is
// a set, and we must use the more time-consuming
// matchesIndexValue check. In practice this happens
// rarely, so we seldom tread this code path.
TransliterationRule* r = (TransliterationRule*) ruleVector->elementAt(j);
if (r->matchesIndexValue((uint8_t)x)) {
v.addElement(r, status);
}
}
}
}
uprv_free(indexValue);
index[256] = v.size();
/* Freeze things into an array.
*/
uprv_free(rules); // Contains alias pointers
/* You can't do malloc(0)! */
if (v.size() == 0) {
rules = NULL;
return;
}
rules = (TransliterationRule **)uprv_malloc(v.size() * sizeof(TransliterationRule *));
/* test for NULL */
if (rules == 0) {
status = U_MEMORY_ALLOCATION_ERROR;
return;
}
for (j=0; j<v.size(); ++j) {
rules[j] = (TransliterationRule*) v.elementAt(j);
}
// TODO Add error reporting that indicates the rules that
// are being masked.
//UnicodeString errors;
/* Check for masking. This is MUCH faster than our old check,
* which was each rule against each following rule, since we
* only have to check for masking within each bin now. It's
* 256*O(n2^2) instead of O(n1^2), where n1 is the total rule
* count, and n2 is the per-bin rule count. But n2<<n1, so
* it's a big win.
*/
for (x=0; x<256; ++x) {
for (j=index[x]; j<index[x+1]-1; ++j) {
TransliterationRule* r1 = rules[j];
for (int32_t k=j+1; k<index[x+1]; ++k) {
TransliterationRule* r2 = rules[k];
if (r1->masks(*r2)) {
//| if (errors == null) {
//| errors = new StringBuffer();
//| } else {
//| errors.append("\n");
//| }
//| errors.append("Rule " + r1 + " masks " + r2);
status = U_RULE_MASK_ERROR;
maskingError(*r1, *r2, parseError);
return;
}
}
}
}
//if (errors != null) {
// throw new IllegalArgumentException(errors.toString());
//}
}
/**
* Transliterate the given text with the given UTransPosition
* indices. Return TRUE if the transliteration should continue
* or FALSE if it should halt (because of a U_PARTIAL_MATCH match).
* Note that FALSE is only ever returned if isIncremental is TRUE.
* @param text the text to be transliterated
* @param pos the position indices, which will be updated
* @param incremental if TRUE, assume new text may be inserted
* at index.limit, and return FALSE if thre is a partial match.
* @return TRUE unless a U_PARTIAL_MATCH has been obtained,
* indicating that transliteration should stop until more text
* arrives.
*/
UBool TransliterationRuleSet::transliterate(Replaceable& text,
UTransPosition& pos,
UBool incremental) {
int16_t indexByte = (int16_t) (text.char32At(pos.start) & 0xFF);
for (int32_t i=index[indexByte]; i<index[indexByte+1]; ++i) {
UMatchDegree m = rules[i]->matchAndReplace(text, pos, incremental);
switch (m) {
case U_MATCH:
_debugOut("match", rules[i], text, pos);
return TRUE;
case U_PARTIAL_MATCH:
_debugOut("partial match", rules[i], text, pos);
return FALSE;
default: /* Ram: added default to make GCC happy */
break;
}
}
// No match or partial match from any rule
pos.start += UTF_CHAR_LENGTH(text.char32At(pos.start));
_debugOut("no match", NULL, text, pos);
return TRUE;
}
/**
* Create rule strings that represents this rule set.
*/
UnicodeString& TransliterationRuleSet::toRules(UnicodeString& ruleSource,
UBool escapeUnprintable) const {
int32_t i;
int32_t count = ruleVector->size();
ruleSource.truncate(0);
for (i=0; i<count; ++i) {
if (i != 0) {
ruleSource.append((UChar) 0x000A /*\n*/);
}
TransliterationRule *r =
(TransliterationRule*) ruleVector->elementAt(i);
r->toRule(ruleSource, escapeUnprintable);
}
return ruleSource;
}
/**
* Return the set of all characters that may be modified
* (getTarget=false) or emitted (getTarget=true) by this set.
*/
UnicodeSet& TransliterationRuleSet::getSourceTargetSet(UnicodeSet& result,
UBool getTarget) const {
result.clear();
int32_t count = ruleVector->size();
for (int32_t i=0; i<count; ++i) {
TransliterationRule* r =
(TransliterationRule*) ruleVector->elementAt(i);
if (getTarget) {
r->addTargetSetTo(result);
} else {
r->addSourceSetTo(result);
}
}
return result;
}
U_NAMESPACE_END