X-Git-Url: http://plrg.eecs.uci.edu/git/?a=blobdiff_plain;f=include%2Fllvm%2FSupport%2FStringPool.h;h=de05e0b547a1bf15f2a427fac36e7ae3d23ecbc8;hb=b4e971f376f15325d6918d7fae0c28c8dad5a78c;hp=7ac2b147c34dc7eb54c0ff355f1166cb676a3ce5;hpb=8d1ea750601cd27f5d70cef1186864abcf57bdb1;p=oota-llvm.git diff --git a/include/llvm/Support/StringPool.h b/include/llvm/Support/StringPool.h index 7ac2b147c34..de05e0b547a 100644 --- a/include/llvm/Support/StringPool.h +++ b/include/llvm/Support/StringPool.h @@ -1,29 +1,29 @@ -//===-- StringPool.h - Interned string pool -------------------------------===// +//===-- StringPool.h - Interned string pool ---------------------*- C++ -*-===// // // The LLVM Compiler Infrastructure // -// This file was developed by Gordon Henriksen and is distributed under the -// University of Illinois Open Source License. See LICENSE.TXT for details. +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. // //===----------------------------------------------------------------------===// // // This file declares an interned string pool, which helps reduce the cost of // strings by using the same storage for identical strings. -// +// // To intern a string: -// +// // StringPool Pool; // PooledStringPtr Str = Pool.intern("wakka wakka"); -// +// // To use the value of an interned string, use operator bool and operator*: -// +// // if (Str) // cerr << "the string is" << *Str << "\n"; -// +// // Pooled strings are immutable, but you can change a PooledStringPtr to point // to another instance. So that interned strings can eventually be freed, // strings in the string pool are reference-counted (automatically). -// +// //===----------------------------------------------------------------------===// #ifndef LLVM_SUPPORT_STRINGPOOL_H @@ -46,32 +46,31 @@ namespace llvm { struct PooledString { StringPool *Pool; ///< So the string can remove itself. unsigned Refcount; ///< Number of referencing PooledStringPtrs. - + public: PooledString() : Pool(0), Refcount(0) { } }; - + friend class PooledStringPtr; - + typedef StringMap table_t; typedef StringMapEntry entry_t; table_t InternTable; - + public: StringPool(); ~StringPool(); - + /// intern - Adds a string to the pool and returns a reference-counted /// pointer to it. No additional memory is allocated if the string already /// exists in the pool. - PooledStringPtr intern(const char *Begin, const char *End); - - /// intern - Adds a null-terminated string to the pool and returns a - /// reference-counted pointer to it. No additional memory is allocated if - /// the string already exists in the pool. - inline PooledStringPtr intern(const char *Str); + PooledStringPtr intern(StringRef Str); + + /// empty - Checks whether the pool is empty. Returns true if so. + /// + inline bool empty() const { return InternTable.empty(); } }; - + /// PooledStringPtr - A pointer to an interned string. Use operator bool to /// test whether the pointer is valid, and operator * to get the string if so. /// This is a lightweight value class with storage requirements equivalent to @@ -80,18 +79,18 @@ namespace llvm { class PooledStringPtr { typedef StringPool::entry_t entry_t; entry_t *S; - + public: PooledStringPtr() : S(0) {} - + explicit PooledStringPtr(entry_t *E) : S(E) { if (S) ++S->getValue().Refcount; } - + PooledStringPtr(const PooledStringPtr &That) : S(That.S) { if (S) ++S->getValue().Refcount; } - + PooledStringPtr &operator=(const PooledStringPtr &That) { if (S != That.S) { clear(); @@ -100,44 +99,40 @@ namespace llvm { } return *this; } - + void clear() { if (!S) return; if (--S->getValue().Refcount == 0) { S->getValue().Pool->InternTable.remove(S); - delete S; + S->Destroy(); } S = 0; } - + ~PooledStringPtr() { clear(); } - + inline const char *begin() const { assert(*this && "Attempt to dereference empty PooledStringPtr!"); return S->getKeyData(); } - + inline const char *end() const { assert(*this && "Attempt to dereference empty PooledStringPtr!"); return S->getKeyData() + S->getKeyLength(); } - + inline unsigned size() const { assert(*this && "Attempt to dereference empty PooledStringPtr!"); return S->getKeyLength(); } - + inline const char *operator*() const { return begin(); } inline operator bool() const { return S != 0; } - + inline bool operator==(const PooledStringPtr &That) { return S == That.S; } inline bool operator!=(const PooledStringPtr &That) { return S != That.S; } }; - - PooledStringPtr StringPool::intern(const char *Str) { - return intern(Str, Str + strlen(Str)); - } } // End llvm namespace