Move Stringpool offsets into a chunked_vector indexed by keys.

4 files changed, 136 insertions, 60 deletions

diff --git a/gold/merge.cc b/gold/merge.cc
index 2c76759..01f2a9e 100644
--- a/gold/merge.cc
+++ b/gold/merge.cc
@@ -520,12 +520,13 @@ Output_merge_string<Char_type>::do_add_input_section(Relobj* object,
 	    }
 	}
 
+      Stringpool::Key key;
       const Char_type* str = this->stringpool_.add_with_length(p, pl - p, true,
-							       NULL);
+							       &key);
 
       section_size_type bytelen_with_null = ((pl - p) + 1) * sizeof(Char_type);
       this->merged_strings_.push_back(Merged_string(object, shndx, i, str,
-						    bytelen_with_null));
+						    bytelen_with_null, key));
 
       p = pl + 1;
       i += bytelen_with_null;
@@ -551,10 +552,8 @@ Output_merge_string<Char_type>::finalize_merged_data()
        p != this->merged_strings_.end();
        ++p)
     {
-      size_t charlen_without_null = (p->length / sizeof(Char_type)) - 1;
       section_offset_type offset =
-	this->stringpool_.get_offset_with_length(p->string,
-						 charlen_without_null);
+	this->stringpool_.get_offset_from_key(p->stringpool_key);
       this->add_mapping(p->object, p->shndx, p->offset, p->length, offset);
     }
 
diff --git a/gold/merge.h b/gold/merge.h
index 056c2c6..bf6a407 100644
--- a/gold/merge.h
+++ b/gold/merge.h
@@ -279,12 +279,14 @@ class Output_merge_string : public Output_merge_base
     const Char_type* string;
     // The length of the string in bytes, including the null terminator.
     size_t length;
+    // The key in the Stringpool.
+    Stringpool::Key stringpool_key;
 
     Merged_string(Relobj *objecta, unsigned int shndxa,
 		  section_offset_type offseta, const Char_type* stringa,
-		  size_t lengtha)
+		  size_t lengtha, Stringpool::Key stringpool_keya)
       : object(objecta), shndx(shndxa), offset(offseta), string(stringa),
-	length(lengtha)
+	length(lengtha), stringpool_key(stringpool_keya)
     { }
   };
 
diff --git a/gold/stringpool.cc b/gold/stringpool.cc
index 9ba505a..0e92ec1 100644
--- a/gold/stringpool.cc
+++ b/gold/stringpool.cc
@@ -35,8 +35,8 @@ namespace gold
 
 template<typename Stringpool_char>
 Stringpool_template<Stringpool_char>::Stringpool_template()
-  : string_set_(), strings_(), strtab_size_(0), next_index_(1),
-    next_uncopied_key_(-1), zero_null_(true)
+  : string_set_(), key_to_offset_(), strings_(), strtab_size_(0),
+    zero_null_(true)
 {
 }
 
@@ -49,6 +49,7 @@ Stringpool_template<Stringpool_char>::clear()
        ++p)
     delete[] reinterpret_cast<char*>(*p);
   this->strings_.clear();
+  this->key_to_offset_.clear();
   this->string_set_.clear();
 }
 
@@ -67,6 +68,8 @@ template<typename Stringpool_char>
 void
 Stringpool_template<Stringpool_char>::reserve(unsigned int n)
 {
+  this->key_to_offset_.reserve(n);
+
 #if defined(HAVE_TR1_UNORDERED_MAP)
   // rehash() implementation is broken in gcc 4.0.3's stl
   //this->string_set_.rehash(this->string_set_.size() + n);
@@ -180,8 +183,7 @@ Stringpool_template<Stringpool_char>::string_hash(const Stringpool_char* s,
 template<typename Stringpool_char>
 const Stringpool_char*
 Stringpool_template<Stringpool_char>::add_string(const Stringpool_char* s,
-						 size_t len,
-						 Key* pkey)
+						 size_t len)
 {
   // We are in trouble if we've already computed the string offsets.
   gold_assert(this->strtab_size_ == 0);
@@ -218,9 +220,6 @@ Stringpool_template<Stringpool_char>::add_string(const Stringpool_char* s,
 	  memset(ret + len - sizeof(Stringpool_char), 0,
 		 sizeof(Stringpool_char));
 
-	  if (pkey != NULL)
-	    *pkey = psd->index * key_mult + psd->len;
-
 	  psd->len += len;
 
 	  return reinterpret_cast<const Stringpool_char*>(ret);
@@ -233,15 +232,6 @@ Stringpool_template<Stringpool_char>::add_string(const Stringpool_char* s,
   memset(psd->data + len - sizeof(Stringpool_char), 0,
 	 sizeof(Stringpool_char));
   psd->len = len;
-  psd->index = this->next_index_;
-  ++this->next_index_;
-
-  if (pkey != NULL)
-    {
-      *pkey = psd->index * key_mult;
-      // Ensure there was no overflow.
-      gold_assert(*pkey / key_mult == psd->index);
-    }
 
   if (front)
     this->strings_.push_front(psd);
@@ -270,15 +260,14 @@ Stringpool_template<Stringpool_char>::add_with_length(const Stringpool_char* s,
 {
   typedef std::pair<typename String_set_type::iterator, bool> Insert_type;
 
+  const Key k = this->key_to_offset_.size();
+
   if (!copy)
     {
       // When we don't need to copy the string, we can call insert
       // directly.
 
-      const Key k = this->next_uncopied_key_;
-      const section_offset_type ozero = 0;
-      std::pair<Hashkey, Hashval> element(Hashkey(s, length),
-					  std::make_pair(k, ozero));
+      std::pair<Hashkey, Hashval> element(Hashkey(s, length), k);
 
       Insert_type ins = this->string_set_.insert(element);
 
@@ -288,15 +277,15 @@ Stringpool_template<Stringpool_char>::add_with_length(const Stringpool_char* s,
 	{
 	  // We just added the string.  The key value has now been
 	  // used.
-	  --this->next_uncopied_key_;
+	  this->key_to_offset_.push_back(0);
 	}
       else
 	{
-	  gold_assert(k != p->second.first);
+	  gold_assert(k != p->second);
 	}
 
       if (pkey != NULL)
-	*pkey = p->second.first;
+	*pkey = p->second;
       return p->first.string;
     }
 
@@ -310,17 +299,17 @@ Stringpool_template<Stringpool_char>::add_with_length(const Stringpool_char* s,
   if (p != this->string_set_.end())
     {
       if (pkey != NULL)
-	*pkey = p->second.first;
+	*pkey = p->second;
       return p->first.string;
     }
 
-  Key k;
-  hk.string = this->add_string(s, length, &k);
+  this->key_to_offset_.push_back(0);
+
+  hk.string = this->add_string(s, length);
   // The contents of the string stay the same, so we don't need to
   // adjust hk.hash_code or hk.length.
 
-  const section_offset_type ozero = 0;
-  std::pair<Hashkey, Hashval> element(hk, std::make_pair(k, ozero));
+  std::pair<Hashkey, Hashval> element(hk, k);
 
   Insert_type ins = this->string_set_.insert(element);
   gold_assert(ins.second);
@@ -341,7 +330,7 @@ Stringpool_template<Stringpool_char>::find(const Stringpool_char* s,
     return NULL;
 
   if (pkey != NULL)
-    *pkey = p->second.first;
+    *pkey = p->second;
 
   return p->first.string;
 }
@@ -423,11 +412,12 @@ Stringpool_template<Stringpool_char>::set_string_offsets()
            curr != this->string_set_.end();
            curr++)
         {
+	  section_offset_type* poff = &this->key_to_offset_[curr->second];
           if (this->zero_null_ && curr->first.string[0] == 0)
-            curr->second.second = 0;
+            *poff = 0;
           else
             {
-              curr->second.second = offset;
+              *poff = offset;
               offset += (curr->first.length + 1) * charsize;
             }
         }
@@ -446,27 +436,30 @@ Stringpool_template<Stringpool_char>::set_string_offsets()
 
       std::sort(v.begin(), v.end(), Stringpool_sort_comparison());
 
+      section_offset_type last_offset = -1;
       for (typename std::vector<Stringpool_sort_info>::iterator last = v.end(),
              curr = v.begin();
            curr != v.end();
            last = curr++)
         {
+	  section_offset_type this_offset;
           if (this->zero_null_ && (*curr)->first.string[0] == 0)
-            (*curr)->second.second = 0;
+            this_offset = 0;
           else if (last != v.end()
                    && is_suffix((*curr)->first.string,
 				(*curr)->first.length,
                                 (*last)->first.string,
 				(*last)->first.length))
-            (*curr)->second.second = ((*last)->second.second
-				      + (((*last)->first.length
-					  - (*curr)->first.length)
-					 * charsize));
+            this_offset = (last_offset
+			   + (((*last)->first.length - (*curr)->first.length)
+			      * charsize));
           else
             {
-              (*curr)->second.second = offset;
+              this_offset = offset;
               offset += ((*curr)->first.length + 1) * charsize;
             }
+	  this->key_to_offset_[(*curr)->second] = this_offset;
+	  last_offset = this_offset;
         }
     }
 
@@ -494,7 +487,7 @@ Stringpool_template<Stringpool_char>::get_offset_with_length(
   Hashkey hk(s, length);
   typename String_set_type::const_iterator p = this->string_set_.find(hk);
   if (p != this->string_set_.end())
-    return p->second.second;
+    return this->key_to_offset_[p->second];
   gold_unreachable();
 }
 
@@ -515,9 +508,10 @@ Stringpool_template<Stringpool_char>::write_to_buffer(
        ++p)
     {
       const int len = (p->first.length + 1) * sizeof(Stringpool_char);
-      gold_assert(static_cast<section_size_type>(p->second.second) + len
+      const section_offset_type offset = this->key_to_offset_[p->second];
+      gold_assert(static_cast<section_size_type>(offset) + len
 		  <= this->strtab_size_);
-      memcpy(buffer + p->second.second, p->first.string, len);
+      memcpy(buffer + offset, p->first.string, len);
     }
 }
 
diff --git a/gold/stringpool.h b/gold/stringpool.h
index 773bfc1..0257894 100644
--- a/gold/stringpool.h
+++ b/gold/stringpool.h
@@ -22,6 +22,7 @@
 
 #include <string>
 #include <list>
+#include <vector>
 
 #ifndef GOLD_STRINGPOOL_H
 #define GOLD_STRINGPOOL_H
@@ -56,8 +57,9 @@ class Output_file;
 // single zero byte, as required for SHT_STRTAB sections.  This
 // conversion is only permitted after all strings have been added to
 // the Stringpool.  After doing this conversion, you can ask for the
-// offset of any string in the stringpool in the string table, and you
-// can write the resulting string table to an output file.
+// offset of any string (or any key) in the stringpool in the string
+// table, and you can write the resulting string table to an output
+// file.
 
 // When a Stringpool is turned into a string table, then as an
 // optimization it will reuse string suffixes to avoid duplicating
@@ -65,6 +67,79 @@ class Output_file;
 // string "abc" will be stored, and "bc" will be represented by an
 // offset into the middle of the string "abc".
 
+
+// A simple chunked vector class--this is a subset of std::vector
+// which stores memory in chunks.  We don't provide iterators, because
+// we don't need them.
+
+template<typename Element>
+class Chunked_vector
+{
+ public:
+  Chunked_vector()
+    : chunks_()
+  { }
+
+  // Clear the elements.
+  void
+  clear()
+  { this->chunks_.clear(); }
+
+  // Reserve elements.
+  void
+  reserve(unsigned int n)
+  {
+    n += chunk_size - 1;
+    while (n >= chunk_size)
+      {
+	this->chunks_.push_back(Element_vector());
+	this->chunks_.back().reserve(chunk_size);
+	n -= chunk_size;
+      }
+  }
+
+  // Get the number of elements.
+  size_t
+  size() const
+  {
+    if (this->chunks_.empty())
+      return 0;
+    else
+      return ((this->chunks_.size() - 1) * chunk_size
+	      + this->chunks_.back().size());
+  }
+
+  // Push a new element on the back of the vector.
+  void
+  push_back(const Element& element)
+  {
+    if (this->chunks_.empty() || this->chunks_.back().size() == chunk_size)
+      {
+	this->chunks_.push_back(Element_vector());
+	this->chunks_.back().reserve(chunk_size);
+      }
+    this->chunks_.back().push_back(element);
+  }
+
+  // Return a reference to an entry in the vector.
+  Element&
+  operator[](size_t i)
+  { return this->chunks_[i / chunk_size][i % chunk_size]; }
+
+  const Element&
+  operator[](size_t i) const
+  { return this->chunks_[i / chunk_size][i % chunk_size]; }
+
+ private:
+  static const unsigned int chunk_size = 8192;
+
+  typedef std::vector<Element> Element_vector;
+  typedef std::vector<Element_vector> Chunk_vector;
+
+  Chunk_vector chunks_;
+};
+
+
 // Stringpools are implemented in terms of Stringpool_template, which
 // is generalized on the type of character used for the strings.  Most
 // uses will want the Stringpool type which uses char.  Other cases
@@ -141,6 +216,14 @@ class Stringpool_template
   section_offset_type
   get_offset_with_length(const Stringpool_char* s, size_t length) const;
 
+  // Get the offset of the string with key K.
+  section_offset_type
+  get_offset_from_key(Key k) const
+  {
+    gold_assert(k < this->key_to_offset_.size());
+    return this->key_to_offset_[k];
+  }
+
   // Get the size of the string table.  This returns the number of
   // bytes, not in units of Stringpool_char.
   section_size_type
@@ -189,15 +272,13 @@ class Stringpool_template
     size_t len;
     // Allocated size of buffer.
     size_t alc;
-    // Buffer index.
-    unsigned int index;
     // Buffer.
     char data[1];
   };
 
   // Copy a string into the buffers, returning a canonical string.
   const Stringpool_char*
-  add_string(const Stringpool_char*, size_t, Key*);
+  add_string(const Stringpool_char*, size_t);
 
   // Return whether s1 is a suffix of s2.
   static bool
@@ -249,11 +330,9 @@ class Stringpool_template
     operator()(const Hashkey&, const Hashkey&) const;
   };
 
-  // The hash table is a map from strings to a pair of Key and string
-  // table offsets.  We only use the offsets if we turn this into an
-  // string table section.
+  // The hash table is a map from strings to Keys.
 
-  typedef std::pair<Key, section_offset_type> Hashval;
+  typedef Key Hashval;
 
   typedef Unordered_map<Hashkey, Hashval, Stringpool_hash,
 			Stringpool_eq> String_set_type;
@@ -268,19 +347,21 @@ class Stringpool_template
     operator()(const Stringpool_sort_info&, const Stringpool_sort_info&) const;
   };
 
+  // Keys map to offsets via a Chunked_vector.  We only use the
+  // offsets if we turn this into an string table section.
+  typedef Chunked_vector<section_offset_type> Key_to_offset;
+
   // List of Stringdata structures.
   typedef std::list<Stringdata*> Stringdata_list;
 
   // Mapping from const char* to namepool entry.
   String_set_type string_set_;
+  // Mapping from Key to string table offset.
+  Key_to_offset key_to_offset_;
   // List of buffers.
   Stringdata_list strings_;
   // Size of string table.
   section_size_type strtab_size_;
-  // Next Stringdata index.
-  unsigned int next_index_;
-  // Next key value for a string we don't copy.
-  int next_uncopied_key_;
   // Whether to reserve offset 0 to hold the null string.
   bool zero_null_;
 };