tor-browser

The Tor Browser
git clone https://git.dasho.dev/tor-browser.git
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HashNames.cpp (3067B)

      1 //
      2 // Copyright 2017 The ANGLE Project Authors. All rights reserved.
      3 // Use of this source code is governed by a BSD-style license that can be
      4 // found in the LICENSE file.
      5 //
      6 
      7 #include "compiler/translator/HashNames.h"
      8 
      9 #include "compiler/translator/ImmutableString.h"
     10 #include "compiler/translator/ImmutableStringBuilder.h"
     11 #include "compiler/translator/IntermNode.h"
     12 #include "compiler/translator/Symbol.h"
     13 
     14 namespace sh
     15 {
     16 
     17 namespace
     18 {
     19 constexpr const ImmutableString kHashedNamePrefix("webgl_");
     20 
     21 ImmutableString HashName(const ImmutableString &name, ShHashFunction64 hashFunction)
     22 {
     23    ASSERT(!name.empty());
     24    ASSERT(hashFunction);
     25    khronos_uint64_t number = (*hashFunction)(name.data(), name.length());
     26 
     27    // Build the hashed name in place.
     28    static const unsigned int kHexStrMaxLength = sizeof(number) * 2;
     29    static const size_t kHashedNameMaxLength   = kHashedNamePrefix.length() + kHexStrMaxLength;
     30 
     31    ImmutableStringBuilder hashedName(kHashedNameMaxLength);
     32    hashedName << kHashedNamePrefix;
     33 
     34    hashedName.appendHex(number);
     35 
     36    return hashedName;
     37 }
     38 
     39 void AddToNameMapIfNotMapped(const ImmutableString &name,
     40                             const ImmutableString &hashedName,
     41                             NameMap *nameMap)
     42 {
     43    if (nameMap)
     44    {
     45        NameMap::const_iterator it = nameMap->find(name.data());
     46        if (it != nameMap->end())
     47        {
     48            // (How bout returning?)
     49            return;
     50        }
     51        (*nameMap)[name.data()] = hashedName.data();
     52    }
     53 }
     54 
     55 }  // anonymous namespace
     56 
     57 ImmutableString HashName(const ImmutableString &name,
     58                         ShHashFunction64 hashFunction,
     59                         NameMap *nameMap)
     60 {
     61    const ImmutableString kUnhashedNamePrefix(kUserDefinedNamePrefix);
     62 
     63    if (hashFunction == nullptr)
     64    {
     65        if (name.length() + kUnhashedNamePrefix.length() > kESSLMaxIdentifierLength)
     66        {
     67            // If the identifier length is already close to the limit, we can't prefix it. This is
     68            // not a problem since there are no builtins or ANGLE's internal variables that would
     69            // have as long names and could conflict.
     70            return name;
     71        }
     72        ImmutableStringBuilder prefixedName(kUnhashedNamePrefix.length() + name.length());
     73        prefixedName << kUnhashedNamePrefix << name;
     74        ImmutableString res = prefixedName;
     75        AddToNameMapIfNotMapped(name, res, nameMap);
     76        return res;
     77    }
     78 
     79    // Has a hash function
     80    ImmutableString hashedName = HashName(name, hashFunction);
     81    AddToNameMapIfNotMapped(name, hashedName, nameMap);
     82    return hashedName;
     83 }
     84 
     85 ImmutableString HashName(const TSymbol *symbol, ShHashFunction64 hashFunction, NameMap *nameMap)
     86 {
     87    if (symbol->symbolType() == SymbolType::Empty)
     88    {
     89        return kEmptyImmutableString;
     90    }
     91    if (symbol->symbolType() == SymbolType::AngleInternal ||
     92        symbol->symbolType() == SymbolType::BuiltIn)
     93    {
     94        return symbol->name();
     95    }
     96    return HashName(symbol->name(), hashFunction, nameMap);
     97 }
     98 
     99 }  // namespace sh