folly::symbolizer::ElfCache Class Reference

#include <ElfCache.h>

Inheritance diagram for folly::symbolizer::ElfCache:

Classes
struct	Entry

Public Member Functions
	ElfCache (size_t capacity)
std::shared_ptr< ElfFile >	getFile (StringPiece path) override
Public Member Functions inherited from folly::symbolizer::ElfCacheBase
virtual	~ElfCacheBase ()

Private Types
typedef boost::intrusive::list_member_hook	LruLink
typedef boost::intrusive::list< Entry, boost::intrusive::member_hook< Entry, LruLink,&Entry::lruLink >, boost::intrusive::constant_time_size< false > >	LruList

Static Private Member Functions
static std::shared_ptr< ElfFile >	filePtr (const std::shared_ptr< Entry > &e)

Private Attributes
std::mutex	mutex_
size_t	capacity_
std::unordered_map< StringPiece, std::shared_ptr< Entry >, Hash >	files_
LruList	lruList_

Detailed Description

General-purpose ELF file cache.

LRU of given capacity. MT-safe (uses locking). Not async-signal-safe.

Definition at line 118 of file ElfCache.h.

Member Typedef Documentation

typedef boost::intrusive::list_member_hook folly::symbolizer::ElfCache::LruLink

private

Definition at line 127 of file ElfCache.h.

typedef boost::intrusive::list< Entry, boost::intrusive::member_hook<Entry, LruLink, &Entry::lruLink>, boost::intrusive::constant_time_size<false> > folly::symbolizer::ElfCache::LruList

private

Definition at line 144 of file ElfCache.h.

Constructor & Destructor Documentation

folly::symbolizer::ElfCache::ElfCache ( size_t  capacity )

explicit

Definition at line 92 of file ElfCache.cpp.

: capacity_(capacity) {}

Member Function Documentation

std::shared_ptr< ElfFile > folly::symbolizer::ElfCache::filePtr ( const std::shared_ptr< Entry > &  e )

staticprivate

Definition at line 129 of file ElfCache.cpp.

Referenced by getFile().

                                                                      {
  // share ownership
  return std::shared_ptr<ElfFile>(e, &e->file);
}

std::shared_ptr< ElfFile > folly::symbolizer::ElfCache::getFile ( StringPiece  path )

overridevirtual

Implements folly::symbolizer::ElfCacheBase.

Definition at line 94 of file ElfCache.cpp.

References capacity_, filePtr(), files_, folly::symbolizer::ElfFile::kSuccess, folly::lock(), lruList_, mutex_, and folly::Range< Iter >::str().

                                                      {
  std::lock_guard<std::mutex> lock(mutex_);

  auto pos = files_.find(p);
  if (pos != files_.end()) {
    // Found, move to back (MRU)
    auto& entry = pos->second;
    lruList_.erase(lruList_.iterator_to(*entry));
    lruList_.push_back(*entry);
    return filePtr(entry);
  }

  auto entry = std::make_shared<Entry>();
  entry->path = p.str();
  auto& path = entry->path;

  // No negative caching
  const char* msg = "";
  int r = entry->file.openAndFollow(path.c_str(), true, &msg);
  if (r != ElfFile::kSuccess) {
    return nullptr;
  }

  if (files_.size() == capacity_) {
    auto& e = lruList_.front();
    lruList_.pop_front();
    files_.erase(e.path);
  }

  files_.emplace(entry->path, entry);
  lruList_.push_back(*entry);

  return filePtr(entry);
}

Member Data Documentation

size_t folly::symbolizer::ElfCache::capacity_

private

Definition at line 137 of file ElfCache.h.

Referenced by getFile().

std::unordered_map<StringPiece, std::shared_ptr<Entry>, Hash> folly::symbolizer::ElfCache::files_

private

Definition at line 138 of file ElfCache.h.

Referenced by getFile().

LruList folly::symbolizer::ElfCache::lruList_

private

Definition at line 145 of file ElfCache.h.

Referenced by getFile().

std::mutex folly::symbolizer::ElfCache::mutex_

private

Definition at line 125 of file ElfCache.h.

Referenced by getFile().

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The documentation for this class was generated from the following files:

• proxygen/folly/folly/experimental/symbolizer/ElfCache.h
• proxygen/folly/folly/experimental/symbolizer/ElfCache.cpp