Move the on-disk hash table code into its own header. No functionality change.

llvm-svn: 69580

1 files changed, 2 insertions, 160 deletions

diff --git a/clang/tools/clang-cc/CacheTokens.cpp b/clang/tools/clang-cc/CacheTokens.cpp
index 2b08818f8f6..a886ba135a1 100644
--- a/clang/tools/clang-cc/CacheTokens.cpp
+++ b/clang/tools/clang-cc/CacheTokens.cpp
@@ -17,6 +17,7 @@
 #include "clang/Basic/SourceManager.h"
 #include "clang/Basic/IdentifierTable.h"
 #include "clang/Basic/Diagnostic.h"
+#include "clang/Basic/OnDiskHashTable.h"
 #include "clang/Lex/Lexer.h"
 #include "clang/Lex/Preprocessor.h"
 #include "llvm/ADT/StringMap.h"
@@ -32,166 +33,7 @@
 #endif
 
 using namespace clang;
-
-typedef uint32_t Offset;
-
-static void Emit8(llvm::raw_ostream& Out, uint32_t V) {
-  Out << (unsigned char)(V);
-}
-
-static void Emit16(llvm::raw_ostream& Out, uint32_t V) {
-  Out << (unsigned char)(V);
-  Out << (unsigned char)(V >>  8);
-  assert((V >> 16) == 0);
-}
-
-static void Emit32(llvm::raw_ostream& Out, uint32_t V) {
-  Out << (unsigned char)(V);
-  Out << (unsigned char)(V >>  8);
-  Out << (unsigned char)(V >> 16);
-  Out << (unsigned char)(V >> 24);
-}
-
-static void Emit64(llvm::raw_ostream& Out, uint64_t V) {
-  Out << (unsigned char)(V);
-  Out << (unsigned char)(V >>  8);
-  Out << (unsigned char)(V >> 16);
-  Out << (unsigned char)(V >> 24);
-  Out << (unsigned char)(V >> 32);
-  Out << (unsigned char)(V >> 40);
-  Out << (unsigned char)(V >> 48);
-  Out << (unsigned char)(V >> 56);
-}
-
-static void Pad(llvm::raw_fd_ostream& Out, unsigned A) {
-  Offset off = (Offset) Out.tell();
-  uint32_t n = ((uintptr_t)(off+A-1) & ~(uintptr_t)(A-1)) - off;
-  for (; n ; --n)
-    Emit8(Out, 0);
-}
-
-// Bernstein hash function:
-// This is basically copy-and-paste from StringMap.  This likely won't
-// stay here, which is why I didn't both to expose this function from
-// String Map.
-static unsigned BernsteinHash(const char* x) {  
-  unsigned int R = 0;
-  for ( ; *x != '\0' ; ++x) R = R * 33 + *x;
-  return R + (R >> 5);
-}
-
-//===----------------------------------------------------------------------===//
-// On Disk Hashtable Logic.  This will eventually get refactored and put
-// elsewhere.
-//===----------------------------------------------------------------------===//
-
-template<typename Info>
-class OnDiskChainedHashTableGenerator {
-  unsigned NumBuckets;
-  unsigned NumEntries;
-  llvm::BumpPtrAllocator BA;
-  
-  class Item {
-  public:
-    typename Info::key_type key;
-    typename Info::data_type data;
-    Item *next;
-    const uint32_t hash;
-    
-    Item(typename Info::key_type_ref k, typename Info::data_type_ref d)
-    : key(k), data(d), next(0), hash(Info::ComputeHash(k)) {}
-  };
-  
-  class Bucket { 
-  public:
-    Offset off;
-    Item*  head;
-    unsigned length;
-    
-    Bucket() {}
-  };
-  
-  Bucket* Buckets;
-  
-private:
-  void insert(Bucket* b, size_t size, Item* E) {
-    unsigned idx = E->hash & (size - 1);
-    Bucket& B = b[idx];
-    E->next = B.head;
-    ++B.length;
-    B.head = E;
-  }
-  
-  void resize(size_t newsize) {
-    Bucket* newBuckets = (Bucket*) calloc(newsize, sizeof(Bucket));
-    // Populate newBuckets with the old entries.
-    for (unsigned i = 0; i < NumBuckets; ++i)
-      for (Item* E = Buckets[i].head; E ; ) {
-        Item* N = E->next;
-        E->next = 0;
-        insert(newBuckets, newsize, E);
-        E = N;
-      }
-    
-    free(Buckets);
-    NumBuckets = newsize;
-    Buckets = newBuckets;
-  }  
-  
-public:
-  
-  void insert(typename Info::key_type_ref key,
-              typename Info::data_type_ref data) {
-
-    ++NumEntries;
-    if (4*NumEntries >= 3*NumBuckets) resize(NumBuckets*2);
-    insert(Buckets, NumBuckets, new (BA.Allocate<Item>()) Item(key, data));
-  }
-  
-  Offset Emit(llvm::raw_fd_ostream& out) {
-    // Emit the payload of the table.
-    for (unsigned i = 0; i < NumBuckets; ++i) {
-      Bucket& B = Buckets[i];
-      if (!B.head) continue;
-      
-      // Store the offset for the data of this bucket.
-      B.off = out.tell();
-      
-      // Write out the number of items in the bucket.
-      Emit16(out, B.length);
-      
-      // Write out the entries in the bucket.
-      for (Item *I = B.head; I ; I = I->next) {
-        Emit32(out, I->hash);
-        const std::pair<unsigned, unsigned>& Len = 
-          Info::EmitKeyDataLength(out, I->key, I->data);
-        Info::EmitKey(out, I->key, Len.first);
-        Info::EmitData(out, I->key, I->data, Len.second);
-      }
-    }
-    
-    // Emit the hashtable itself.
-    Pad(out, 4);
-    Offset TableOff = out.tell();
-    Emit32(out, NumBuckets);
-    Emit32(out, NumEntries);
-    for (unsigned i = 0; i < NumBuckets; ++i) Emit32(out, Buckets[i].off);
-    
-    return TableOff;
-  }
-  
-  OnDiskChainedHashTableGenerator() {
-    NumEntries = 0;
-    NumBuckets = 64;    
-    // Note that we do not need to run the constructors of the individual
-    // Bucket objects since 'calloc' returns bytes that are all 0.
-    Buckets = (Bucket*) calloc(NumBuckets, sizeof(Bucket));
-  }
-  
-  ~OnDiskChainedHashTableGenerator() {
-    free(Buckets);
-  }
-};
+using namespace clang::io;
 
 //===----------------------------------------------------------------------===//
 // PTH-specific stuff.