compilation-cache.cc 6.49 KB
Newer Older
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34
// Copyright 2008 the V8 project authors. All rights reserved.
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
//     * Redistributions of source code must retain the above copyright
//       notice, this list of conditions and the following disclaimer.
//     * Redistributions in binary form must reproduce the above
//       copyright notice, this list of conditions and the following
//       disclaimer in the documentation and/or other materials provided
//       with the distribution.
//     * Neither the name of Google Inc. nor the names of its
//       contributors may be used to endorse or promote products derived
//       from this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

#include "v8.h"

#include "compilation-cache.h"

namespace v8 { namespace internal {

enum {
35
  NUMBER_OF_ENTRY_KINDS = CompilationCache::LAST_ENTRY + 1
36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88
};


// Keep separate tables for the different entry kinds.
static Object* tables[NUMBER_OF_ENTRY_KINDS] = { 0, };


static Handle<CompilationCacheTable> AllocateTable(int size) {
  CALL_HEAP_FUNCTION(CompilationCacheTable::Allocate(size),
                     CompilationCacheTable);
}


static Handle<CompilationCacheTable> GetTable(CompilationCache::Entry entry) {
  Handle<CompilationCacheTable> result;
  if (tables[entry]->IsUndefined()) {
    static const int kInitialCacheSize = 64;
    result = AllocateTable(kInitialCacheSize);
    tables[entry] = *result;
  } else {
    CompilationCacheTable* table = CompilationCacheTable::cast(tables[entry]);
    result = Handle<CompilationCacheTable>(table);
  }
  return result;
}


// We only re-use a cached function for some script source code if the
// script originates from the same places. This is to avoid issues
// when reporting errors, etc.
static bool HasOrigin(Handle<JSFunction> boilerplate,
                      Handle<Object> name,
                      int line_offset,
                      int column_offset) {
  Handle<Script> script =
      Handle<Script>(Script::cast(boilerplate->shared()->script()));
  // If the script name isn't set, the boilerplate script should have
  // an undefined name to have the same origin.
  if (name.is_null()) {
    return script->name()->IsUndefined();
  }
  // Do the fast bailout checks first.
  if (line_offset != script->line_offset()->value()) return false;
  if (column_offset != script->column_offset()->value()) return false;
  // Check that both names are strings. If not, no match.
  if (!name->IsString() || !script->name()->IsString()) return false;
  // Compare the two name strings for equality.
  return String::cast(*name)->Equals(String::cast(script->name()));
}


static Handle<JSFunction> Lookup(Handle<String> source,
                                 CompilationCache::Entry entry) {
89 90 91 92 93 94 95 96
  // Make sure not to leak the table into the surrounding handle
  // scope. Otherwise, we risk keeping old tables around even after
  // having cleared the cache.
  Object* result;
  { HandleScope scope;
    Handle<CompilationCacheTable> table = GetTable(entry);
    result = table->Lookup(*source);
  }
97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134
  if (result->IsJSFunction()) {
    return Handle<JSFunction>(JSFunction::cast(result));
  } else {
    return Handle<JSFunction>::null();
  }
}


Handle<JSFunction> CompilationCache::LookupScript(Handle<String> source,
                                                  Handle<Object> name,
                                                  int line_offset,
                                                  int column_offset) {
  Handle<JSFunction> result = Lookup(source, SCRIPT);
  if (result.is_null()) {
    Counters::compilation_cache_misses.Increment();
  } else if (HasOrigin(result, name, line_offset, column_offset)) {
    Counters::compilation_cache_hits.Increment();
  } else {
    result = Handle<JSFunction>::null();
    Counters::compilation_cache_misses.Increment();
  }
  return result;
}


Handle<JSFunction> CompilationCache::LookupEval(Handle<String> source,
                                                Entry entry) {
  ASSERT(entry == EVAL_GLOBAL || entry == EVAL_CONTEXTUAL);
  Handle<JSFunction> result = Lookup(source, entry);
  if (result.is_null()) {
    Counters::compilation_cache_misses.Increment();
  } else {
    Counters::compilation_cache_hits.Increment();
  }
  return result;
}


135 136 137
void CompilationCache::PutFunction(Handle<String> source,
                                   Entry entry,
                                   Handle<JSFunction> boilerplate) {
138
  HandleScope scope;
139 140 141 142 143 144
  ASSERT(boilerplate->IsBoilerplate());
  Handle<CompilationCacheTable> table = GetTable(entry);
  CALL_HEAP_FUNCTION_VOID(table->Put(*source, *boilerplate));
}


145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167
Handle<FixedArray> CompilationCache::LookupRegExp(Handle<String> source,
                                                  JSRegExp::Flags flags) {
  Handle<CompilationCacheTable> table = GetTable(REGEXP);
  Object* result = table->LookupRegExp(*source, flags);
  if (result->IsFixedArray()) {
    Counters::regexp_cache_hits.Increment();
    return Handle<FixedArray>(FixedArray::cast(result));
  } else {
    Counters::regexp_cache_misses.Increment();
    return Handle<FixedArray>();
  }
}


void CompilationCache::PutRegExp(Handle<String> source,
                                 JSRegExp::Flags flags,
                                 Handle<FixedArray> data) {
  HandleScope scope;
  Handle<CompilationCacheTable> table = GetTable(REGEXP);
  CALL_HEAP_FUNCTION_VOID(table->PutRegExp(*source, flags, *data));
}


168 169 170 171 172 173 174 175 176 177 178 179 180
void CompilationCache::Clear() {
  for (int i = 0; i < NUMBER_OF_ENTRY_KINDS; i++) {
    tables[i] = Heap::undefined_value();
  }
}


void CompilationCache::Iterate(ObjectVisitor* v) {
  v->VisitPointers(&tables[0], &tables[NUMBER_OF_ENTRY_KINDS]);
}


} }  // namespace v8::internal