symbol.cpp revision 3602:da91efe96a93
1/* 2 * Copyright (c) 1997, 2012, 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 "classfile/altHashing.hpp" 28#include "classfile/classLoaderData.hpp" 29#include "oops/symbol.hpp" 30#include "runtime/os.hpp" 31#include "memory/allocation.inline.hpp" 32#include "memory/resourceArea.hpp" 33 34Symbol::Symbol(const u1* name, int length, int refcount) : _refcount(refcount), _length(length) { 35 _identity_hash = os::random(); 36 for (int i = 0; i < _length; i++) { 37 byte_at_put(i, name[i]); 38 } 39} 40 41void* Symbol::operator new(size_t sz, int len, TRAPS) { 42 int alloc_size = size(len)*HeapWordSize; 43 address res = (address) AllocateHeap(alloc_size, mtSymbol); 44 return res; 45} 46 47void* Symbol::operator new(size_t sz, int len, Arena* arena, TRAPS) { 48 int alloc_size = size(len)*HeapWordSize; 49 address res = (address)arena->Amalloc(alloc_size); 50 return res; 51} 52 53void* Symbol::operator new(size_t sz, int len, ClassLoaderData* loader_data, TRAPS) { 54 address res; 55 int alloc_size = size(len)*HeapWordSize; 56 res = (address) Metaspace::allocate(loader_data, size(len), true, 57 Metaspace::NonClassType, CHECK_NULL); 58 return res; 59} 60 61void Symbol::operator delete(void *p) { 62 assert(((Symbol*)p)->refcount() == 0, "should not call this"); 63 FreeHeap(p); 64} 65 66// ------------------------------------------------------------------ 67// Symbol::equals 68// 69// Compares the symbol with a string of the given length. 70bool Symbol::equals(const char* str, int len) const { 71 int l = utf8_length(); 72 if (l != len) return false; 73 while (l-- > 0) { 74 if (str[l] != (char) byte_at(l)) 75 return false; 76 } 77 assert(l == -1, "we should be at the beginning"); 78 return true; 79} 80 81 82// ------------------------------------------------------------------ 83// Symbol::starts_with 84// 85// Tests if the symbol starts with the specified prefix of the given 86// length. 87bool Symbol::starts_with(const char* prefix, int len) const { 88 if (len > utf8_length()) return false; 89 while (len-- > 0) { 90 if (prefix[len] != (char) byte_at(len)) 91 return false; 92 } 93 assert(len == -1, "we should be at the beginning"); 94 return true; 95} 96 97 98// ------------------------------------------------------------------ 99// Symbol::index_of 100// 101// Finds if the given string is a substring of this symbol's utf8 bytes. 102// Return -1 on failure. Otherwise return the first index where str occurs. 103int Symbol::index_of_at(int i, const char* str, int len) const { 104 assert(i >= 0 && i <= utf8_length(), "oob"); 105 if (len <= 0) return 0; 106 char first_char = str[0]; 107 address bytes = (address) ((Symbol*)this)->base(); 108 address limit = bytes + utf8_length() - len; // inclusive limit 109 address scan = bytes + i; 110 if (scan > limit) 111 return -1; 112 for (; scan <= limit; scan++) { 113 scan = (address) memchr(scan, first_char, (limit + 1 - scan)); 114 if (scan == NULL) 115 return -1; // not found 116 assert(scan >= bytes+i && scan <= limit, "scan oob"); 117 if (memcmp(scan, str, len) == 0) 118 return (int)(scan - bytes); 119 } 120 return -1; 121} 122 123 124char* Symbol::as_C_string(char* buf, int size) const { 125 if (size > 0) { 126 int len = MIN2(size - 1, utf8_length()); 127 for (int i = 0; i < len; i++) { 128 buf[i] = byte_at(i); 129 } 130 buf[len] = '\0'; 131 } 132 return buf; 133} 134 135char* Symbol::as_C_string() const { 136 int len = utf8_length(); 137 char* str = NEW_RESOURCE_ARRAY(char, len + 1); 138 return as_C_string(str, len + 1); 139} 140 141char* Symbol::as_C_string_flexible_buffer(Thread* t, 142 char* buf, int size) const { 143 char* str; 144 int len = utf8_length(); 145 int buf_len = len + 1; 146 if (size < buf_len) { 147 str = NEW_RESOURCE_ARRAY(char, buf_len); 148 } else { 149 str = buf; 150 } 151 return as_C_string(str, buf_len); 152} 153 154void Symbol::print_symbol_on(outputStream* st) const { 155 st = st ? st : tty; 156 int length = UTF8::unicode_length((const char*)bytes(), utf8_length()); 157 const char *ptr = (const char *)bytes(); 158 jchar value; 159 for (int index = 0; index < length; index++) { 160 ptr = UTF8::next(ptr, &value); 161 if (value >= 32 && value < 127 || value == '\'' || value == '\\') { 162 st->put(value); 163 } else { 164 st->print("\\u%04x", value); 165 } 166 } 167} 168 169jchar* Symbol::as_unicode(int& length) const { 170 Symbol* this_ptr = (Symbol*)this; 171 length = UTF8::unicode_length((char*)this_ptr->bytes(), utf8_length()); 172 jchar* result = NEW_RESOURCE_ARRAY(jchar, length); 173 if (length > 0) { 174 UTF8::convert_to_unicode((char*)this_ptr->bytes(), result, length); 175 } 176 return result; 177} 178 179const char* Symbol::as_klass_external_name(char* buf, int size) const { 180 if (size > 0) { 181 char* str = as_C_string(buf, size); 182 int length = (int)strlen(str); 183 // Turn all '/'s into '.'s (also for array klasses) 184 for (int index = 0; index < length; index++) { 185 if (str[index] == '/') { 186 str[index] = '.'; 187 } 188 } 189 return str; 190 } else { 191 return buf; 192 } 193} 194 195const char* Symbol::as_klass_external_name() const { 196 char* str = as_C_string(); 197 int length = (int)strlen(str); 198 // Turn all '/'s into '.'s (also for array klasses) 199 for (int index = 0; index < length; index++) { 200 if (str[index] == '/') { 201 str[index] = '.'; 202 } 203 } 204 return str; 205} 206 207// Alternate hashing for unbalanced symbol tables. 208unsigned int Symbol::new_hash(jint seed) { 209 ResourceMark rm; 210 // Use alternate hashing algorithm on this symbol. 211 return AltHashing::murmur3_32(seed, (const jbyte*)as_C_string(), utf8_length()); 212} 213 214void Symbol::print_on(outputStream* st) const { 215 if (this == NULL) { 216 st->print_cr("NULL"); 217 } else { 218 st->print("Symbol: '"); 219 print_symbol_on(st); 220 st->print("'"); 221 st->print(" count %d", refcount()); 222 } 223} 224 225// The print_value functions are present in all builds, to support the 226// disassembler and error reporting. 227void Symbol::print_value_on(outputStream* st) const { 228 if (this == NULL) { 229 st->print("NULL"); 230 } else { 231 st->print("'"); 232 for (int i = 0; i < utf8_length(); i++) { 233 st->print("%c", byte_at(i)); 234 } 235 st->print("'"); 236 } 237} 238 239// SymbolTable prints this in its statistics 240NOT_PRODUCT(int Symbol::_total_count = 0;) 241