symbol.cpp revision 2273:1d1603768966
1/* 2 * Copyright (c) 1997, 2011, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 * 23 */ 24 25 26#include "precompiled.hpp" 27#include "oops/oop.inline.hpp" 28#include "oops/symbol.hpp" 29#include "runtime/os.hpp" 30#include "memory/allocation.inline.hpp" 31 32Symbol::Symbol(const u1* name, int length) : _refcount(0), _length(length) { 33 _identity_hash = os::random(); 34 for (int i = 0; i < _length; i++) { 35 byte_at_put(i, name[i]); 36 } 37} 38 39void* Symbol::operator new(size_t size, int len) { 40 return (void *) AllocateHeap(object_size(len) * HeapWordSize, "symbol"); 41} 42 43// ------------------------------------------------------------------ 44// Symbol::equals 45// 46// Compares the symbol with a string of the given length. 47bool Symbol::equals(const char* str, int len) const { 48 int l = utf8_length(); 49 if (l != len) return false; 50 while (l-- > 0) { 51 if (str[l] != (char) byte_at(l)) 52 return false; 53 } 54 assert(l == -1, "we should be at the beginning"); 55 return true; 56} 57 58 59// ------------------------------------------------------------------ 60// Symbol::starts_with 61// 62// Tests if the symbol starts with the specified prefix of the given 63// length. 64bool Symbol::starts_with(const char* prefix, int len) const { 65 if (len > utf8_length()) return false; 66 while (len-- > 0) { 67 if (prefix[len] != (char) byte_at(len)) 68 return false; 69 } 70 assert(len == -1, "we should be at the beginning"); 71 return true; 72} 73 74 75// ------------------------------------------------------------------ 76// Symbol::index_of 77// 78// Finds if the given string is a substring of this symbol's utf8 bytes. 79// Return -1 on failure. Otherwise return the first index where str occurs. 80int Symbol::index_of_at(int i, const char* str, int len) const { 81 assert(i >= 0 && i <= utf8_length(), "oob"); 82 if (len <= 0) return 0; 83 char first_char = str[0]; 84 address bytes = (address) ((Symbol*)this)->base(); 85 address limit = bytes + utf8_length() - len; // inclusive limit 86 address scan = bytes + i; 87 if (scan > limit) 88 return -1; 89 for (;;) { 90 scan = (address) memchr(scan, first_char, (limit + 1 - scan)); 91 if (scan == NULL) 92 return -1; // not found 93 assert(scan >= bytes+i && scan <= limit, "scan oob"); 94 if (memcmp(scan, str, len) == 0) 95 return (int)(scan - bytes); 96 } 97} 98 99 100char* Symbol::as_C_string(char* buf, int size) const { 101 if (size > 0) { 102 int len = MIN2(size - 1, utf8_length()); 103 for (int i = 0; i < len; i++) { 104 buf[i] = byte_at(i); 105 } 106 buf[len] = '\0'; 107 } 108 return buf; 109} 110 111char* Symbol::as_C_string() const { 112 int len = utf8_length(); 113 char* str = NEW_RESOURCE_ARRAY(char, len + 1); 114 return as_C_string(str, len + 1); 115} 116 117char* Symbol::as_C_string_flexible_buffer(Thread* t, 118 char* buf, int size) const { 119 char* str; 120 int len = utf8_length(); 121 int buf_len = len + 1; 122 if (size < buf_len) { 123 str = NEW_RESOURCE_ARRAY(char, buf_len); 124 } else { 125 str = buf; 126 } 127 return as_C_string(str, buf_len); 128} 129 130void Symbol::print_symbol_on(outputStream* st) const { 131 st = st ? st : tty; 132 int length = UTF8::unicode_length((const char*)bytes(), utf8_length()); 133 const char *ptr = (const char *)bytes(); 134 jchar value; 135 for (int index = 0; index < length; index++) { 136 ptr = UTF8::next(ptr, &value); 137 if (value >= 32 && value < 127 || value == '\'' || value == '\\') { 138 st->put(value); 139 } else { 140 st->print("\\u%04x", value); 141 } 142 } 143} 144 145jchar* Symbol::as_unicode(int& length) const { 146 Symbol* this_ptr = (Symbol*)this; 147 length = UTF8::unicode_length((char*)this_ptr->bytes(), utf8_length()); 148 jchar* result = NEW_RESOURCE_ARRAY(jchar, length); 149 if (length > 0) { 150 UTF8::convert_to_unicode((char*)this_ptr->bytes(), result, length); 151 } 152 return result; 153} 154 155const char* Symbol::as_klass_external_name(char* buf, int size) const { 156 if (size > 0) { 157 char* str = as_C_string(buf, size); 158 int length = (int)strlen(str); 159 // Turn all '/'s into '.'s (also for array klasses) 160 for (int index = 0; index < length; index++) { 161 if (str[index] == '/') { 162 str[index] = '.'; 163 } 164 } 165 return str; 166 } else { 167 return buf; 168 } 169} 170 171const char* Symbol::as_klass_external_name() const { 172 char* str = as_C_string(); 173 int length = (int)strlen(str); 174 // Turn all '/'s into '.'s (also for array klasses) 175 for (int index = 0; index < length; index++) { 176 if (str[index] == '/') { 177 str[index] = '.'; 178 } 179 } 180 return str; 181} 182 183 184void Symbol::print_on(outputStream* st) const { 185 if (this == NULL) { 186 st->print_cr("NULL"); 187 } else { 188 st->print("Symbol: '"); 189 print_symbol_on(st); 190 st->print("'"); 191 st->print(" count %d", refcount()); 192 } 193} 194 195// The print_value functions are present in all builds, to support the 196// disassembler and error reporting. 197void Symbol::print_value_on(outputStream* st) const { 198 if (this == NULL) { 199 st->print("NULL"); 200 } else { 201 st->print("'"); 202 for (int i = 0; i < utf8_length(); i++) { 203 st->print("%c", byte_at(i)); 204 } 205 st->print("'"); 206 } 207} 208 209void Symbol::increment_refcount() { 210 // Only increment the refcount if positive. If negative either 211 // overflow has occurred or it is a permanent symbol in a read only 212 // shared archive. 213 if (_refcount >= 0) { 214 Atomic::inc(&_refcount); 215 NOT_PRODUCT(Atomic::inc(&_total_count);) 216 } 217} 218 219void Symbol::decrement_refcount() { 220 if (_refcount >= 0) { 221 Atomic::dec(&_refcount); 222#ifdef ASSERT 223 if (_refcount < 0) { 224 print(); 225 assert(false, "reference count underflow for symbol"); 226 } 227#endif 228 } 229} 230 231NOT_PRODUCT(int Symbol::_total_count = 0;) 232