JSAtomUtils.h (3529B)
1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- 2 * vim: set ts=8 sts=2 et sw=2 tw=80: 3 * This Source Code Form is subject to the terms of the Mozilla Public 4 * License, v. 2.0. If a copy of the MPL was not distributed with this 5 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ 6 7 #ifndef vm_JSAtomUtils_h 8 #define vm_JSAtomUtils_h 9 10 #include "mozilla/HashFunctions.h" 11 #include "mozilla/Maybe.h" 12 13 #include "NamespaceImports.h" 14 15 #include "gc/MaybeRooted.h" 16 #include "js/TypeDecls.h" 17 #include "js/Utility.h" 18 #include "vm/StringType.h" 19 20 namespace js { 21 22 class AtomSet; 23 24 /* 25 * Return a printable, lossless char[] representation of a string-type atom. 26 * The returned string is guaranteed to contain only ASCII characters. 27 */ 28 extern UniqueChars AtomToPrintableString(JSContext* cx, JSAtom* atom); 29 30 class PropertyName; 31 32 } /* namespace js */ 33 34 namespace js { 35 36 /* 37 * Atom tracing and garbage collection hooks. 38 */ 39 void TraceAtoms(JSTracer* trc); 40 41 extern JSAtom* Atomize( 42 JSContext* cx, const char* bytes, size_t length, 43 const mozilla::Maybe<uint32_t>& indexValue = mozilla::Nothing()); 44 45 extern JSAtom* AtomizeWithoutActiveZone(JSContext* cx, const char* bytes, 46 size_t length); 47 48 template <typename CharT> 49 extern JSAtom* AtomizeChars(JSContext* cx, const CharT* chars, size_t length); 50 51 /* 52 * Optimized entry points for atomization. 53 * 54 * The meaning of suffix: 55 * * "NonStatic": characters don't match StaticStrings 56 * * "ValidLength": length fits JSString::MAX_LENGTH 57 */ 58 59 /* Atomize characters when the value of HashString is already known. */ 60 template <typename CharT> 61 extern JSAtom* AtomizeCharsNonStaticValidLength(JSContext* cx, 62 mozilla::HashNumber hash, 63 const CharT* chars, 64 size_t length); 65 66 /** 67 * Permanently atomize characters. 68 * 69 * `chars` shouldn't match any of StaticStrings entry. 70 * `length` should be validated by JSString::validateLength. 71 */ 72 extern JSAtom* PermanentlyAtomizeCharsNonStaticValidLength( 73 JSContext* cx, AtomSet& atomSet, mozilla::HashNumber hash, 74 const Latin1Char* chars, size_t length); 75 76 /** 77 * Create an atom whose contents are those of the |utf8ByteLength| code units 78 * starting at |utf8Chars|, interpreted as UTF-8. 79 * 80 * Throws if the code units do not contain valid UTF-8. 81 */ 82 extern JSAtom* AtomizeUTF8Chars(JSContext* cx, const char* utf8Chars, 83 size_t utf8ByteLength); 84 85 extern JSAtom* AtomizeStringSlow(JSContext* cx, JSString* str); 86 87 MOZ_ALWAYS_INLINE JSAtom* AtomizeString(JSContext* cx, JSString* str) { 88 // Inlined fast path for atoms. This covers ~71% of calls to this function on 89 // Speedometer 3. 90 if (str->isAtom()) { 91 return &str->asAtom(); 92 } 93 return AtomizeStringSlow(cx, str); 94 } 95 96 template <AllowGC allowGC> 97 extern JSAtom* ToAtom(JSContext* cx, 98 typename MaybeRooted<JS::Value, allowGC>::HandleType v); 99 100 /* 101 * Pin an atom so that it is never collected. Avoid using this if possible. 102 * 103 * This function does not GC. 104 */ 105 extern bool PinAtom(JSContext* cx, JSAtom* atom); 106 107 extern JS::Handle<PropertyName*> ClassName(JSProtoKey key, JSContext* cx); 108 109 #ifdef DEBUG 110 111 bool AtomIsMarked(JS::Zone* zone, JSAtom* atom); 112 bool AtomIsMarked(JS::Zone* zone, jsid id); 113 bool AtomIsMarked(JS::Zone* zone, const JS::Value& value); 114 115 #endif // DEBUG 116 117 } /* namespace js */ 118 119 #endif /* vm_JSAtomUtils_h */