Initial import.

1 files changed, 631 insertions, 0 deletions

diff --git a/chromium/net/disk_cache/mem_entry_impl.cc b/chromium/net/disk_cache/mem_entry_impl.cc
new file mode 100644
index 00000000000..7d0095898b4
--- /dev/null
+++ b/chromium/net/disk_cache/mem_entry_impl.cc
@@ -0,0 +1,631 @@
+// Copyright (c) 2012 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "net/disk_cache/mem_entry_impl.h"
+
+#include "base/bind.h"
+#include "base/logging.h"
+#include "base/strings/stringprintf.h"
+#include "base/values.h"
+#include "net/base/io_buffer.h"
+#include "net/base/net_errors.h"
+#include "net/disk_cache/mem_backend_impl.h"
+#include "net/disk_cache/net_log_parameters.h"
+
+using base::Time;
+
+namespace {
+
+const int kSparseData = 1;
+
+// Maximum size of a sparse entry is 2 to the power of this number.
+const int kMaxSparseEntryBits = 12;
+
+// Sparse entry has maximum size of 4KB.
+const int kMaxSparseEntrySize = 1 << kMaxSparseEntryBits;
+
+// Convert global offset to child index.
+inline int ToChildIndex(int64 offset) {
+  return static_cast<int>(offset >> kMaxSparseEntryBits);
+}
+
+// Convert global offset to offset in child entry.
+inline int ToChildOffset(int64 offset) {
+  return static_cast<int>(offset & (kMaxSparseEntrySize - 1));
+}
+
+// Returns a name for a child entry given the base_name of the parent and the
+// child_id.  This name is only used for logging purposes.
+// If the entry is called entry_name, child entries will be named something
+// like Range_entry_name:YYY where YYY is the number of the particular child.
+std::string GenerateChildName(const std::string& base_name, int child_id) {
+  return base::StringPrintf("Range_%s:%i", base_name.c_str(), child_id);
+}
+
+// Returns NetLog parameters for the creation of a child MemEntryImpl.  Separate
+// function needed because child entries don't suppport GetKey().
+base::Value* NetLogChildEntryCreationCallback(
+    const disk_cache::MemEntryImpl* parent,
+    int child_id,
+    net::NetLog::LogLevel /* log_level */) {
+  base::DictionaryValue* dict = new base::DictionaryValue();
+  dict->SetString("key", GenerateChildName(parent->GetKey(), child_id));
+  dict->SetBoolean("created", true);
+  return dict;
+}
+
+}  // namespace
+
+namespace disk_cache {
+
+MemEntryImpl::MemEntryImpl(MemBackendImpl* backend) {
+  doomed_ = false;
+  backend_ = backend;
+  ref_count_ = 0;
+  parent_ = NULL;
+  child_id_ = 0;
+  child_first_pos_ = 0;
+  next_ = NULL;
+  prev_ = NULL;
+  for (int i = 0; i < NUM_STREAMS; i++)
+    data_size_[i] = 0;
+}
+
+// ------------------------------------------------------------------------
+
+bool MemEntryImpl::CreateEntry(const std::string& key, net::NetLog* net_log) {
+  key_ = key;
+  Time current = Time::Now();
+  last_modified_ = current;
+  last_used_ = current;
+
+  net_log_ = net::BoundNetLog::Make(net_log,
+                                    net::NetLog::SOURCE_MEMORY_CACHE_ENTRY);
+  // Must be called after |key_| is set, so GetKey() works.
+  net_log_.BeginEvent(
+      net::NetLog::TYPE_DISK_CACHE_MEM_ENTRY_IMPL,
+      CreateNetLogEntryCreationCallback(this, true));
+
+  Open();
+  backend_->ModifyStorageSize(0, static_cast<int32>(key.size()));
+  return true;
+}
+
+void MemEntryImpl::InternalDoom() {
+  net_log_.AddEvent(net::NetLog::TYPE_ENTRY_DOOM);
+  doomed_ = true;
+  if (!ref_count_) {
+    if (type() == kParentEntry) {
+      // If this is a parent entry, we need to doom all the child entries.
+      if (children_.get()) {
+        EntryMap children;
+        children.swap(*children_);
+        for (EntryMap::iterator i = children.begin();
+             i != children.end(); ++i) {
+          // Since a pointer to this object is also saved in the map, avoid
+          // dooming it.
+          if (i->second != this)
+            i->second->Doom();
+        }
+        DCHECK(children_->empty());
+      }
+    } else {
+      // If this is a child entry, detach it from the parent.
+      parent_->DetachChild(child_id_);
+    }
+    delete this;
+  }
+}
+
+void MemEntryImpl::Open() {
+  // Only a parent entry can be opened.
+  // TODO(hclam): make sure it's correct to not apply the concept of ref
+  // counting to child entry.
+  DCHECK(type() == kParentEntry);
+  ref_count_++;
+  DCHECK_GE(ref_count_, 0);
+  DCHECK(!doomed_);
+}
+
+bool MemEntryImpl::InUse() {
+  if (type() == kParentEntry) {
+    return ref_count_ > 0;
+  } else {
+    // A child entry is always not in use. The consequence is that a child entry
+    // can always be evicted while the associated parent entry is currently in
+    // used (i.e. opened).
+    return false;
+  }
+}
+
+// ------------------------------------------------------------------------
+
+void MemEntryImpl::Doom() {
+  if (doomed_)
+    return;
+  if (type() == kParentEntry) {
+    // Perform internal doom from the backend if this is a parent entry.
+    backend_->InternalDoomEntry(this);
+  } else {
+    // Manually detach from the backend and perform internal doom.
+    backend_->RemoveFromRankingList(this);
+    InternalDoom();
+  }
+}
+
+void MemEntryImpl::Close() {
+  // Only a parent entry can be closed.
+  DCHECK(type() == kParentEntry);
+  ref_count_--;
+  DCHECK_GE(ref_count_, 0);
+  if (!ref_count_ && doomed_)
+    InternalDoom();
+}
+
+std::string MemEntryImpl::GetKey() const {
+  // A child entry doesn't have key so this method should not be called.
+  DCHECK(type() == kParentEntry);
+  return key_;
+}
+
+Time MemEntryImpl::GetLastUsed() const {
+  return last_used_;
+}
+
+Time MemEntryImpl::GetLastModified() const {
+  return last_modified_;
+}
+
+int32 MemEntryImpl::GetDataSize(int index) const {
+  if (index < 0 || index >= NUM_STREAMS)
+    return 0;
+  return data_size_[index];
+}
+
+int MemEntryImpl::ReadData(int index, int offset, IOBuffer* buf, int buf_len,
+                           const CompletionCallback& callback) {
+  if (net_log_.IsLoggingAllEvents()) {
+    net_log_.BeginEvent(
+        net::NetLog::TYPE_ENTRY_READ_DATA,
+        CreateNetLogReadWriteDataCallback(index, offset, buf_len, false));
+  }
+
+  int result = InternalReadData(index, offset, buf, buf_len);
+
+  if (net_log_.IsLoggingAllEvents()) {
+    net_log_.EndEvent(
+        net::NetLog::TYPE_ENTRY_READ_DATA,
+        CreateNetLogReadWriteCompleteCallback(result));
+  }
+  return result;
+}
+
+int MemEntryImpl::WriteData(int index, int offset, IOBuffer* buf, int buf_len,
+                            const CompletionCallback& callback, bool truncate) {
+  if (net_log_.IsLoggingAllEvents()) {
+    net_log_.BeginEvent(
+        net::NetLog::TYPE_ENTRY_WRITE_DATA,
+        CreateNetLogReadWriteDataCallback(index, offset, buf_len, truncate));
+  }
+
+  int result = InternalWriteData(index, offset, buf, buf_len, truncate);
+
+  if (net_log_.IsLoggingAllEvents()) {
+    net_log_.EndEvent(
+        net::NetLog::TYPE_ENTRY_WRITE_DATA,
+        CreateNetLogReadWriteCompleteCallback(result));
+  }
+  return result;
+}
+
+int MemEntryImpl::ReadSparseData(int64 offset, IOBuffer* buf, int buf_len,
+                                 const CompletionCallback& callback) {
+  if (net_log_.IsLoggingAllEvents()) {
+    net_log_.BeginEvent(
+        net::NetLog::TYPE_SPARSE_READ,
+        CreateNetLogSparseOperationCallback(offset, buf_len));
+  }
+  int result = InternalReadSparseData(offset, buf, buf_len);
+  if (net_log_.IsLoggingAllEvents())
+    net_log_.EndEvent(net::NetLog::TYPE_SPARSE_READ);
+  return result;
+}
+
+int MemEntryImpl::WriteSparseData(int64 offset, IOBuffer* buf, int buf_len,
+                                  const CompletionCallback& callback) {
+  if (net_log_.IsLoggingAllEvents()) {
+    net_log_.BeginEvent(
+        net::NetLog::TYPE_SPARSE_WRITE,
+        CreateNetLogSparseOperationCallback(offset, buf_len));
+  }
+  int result = InternalWriteSparseData(offset, buf, buf_len);
+  if (net_log_.IsLoggingAllEvents())
+    net_log_.EndEvent(net::NetLog::TYPE_SPARSE_WRITE);
+  return result;
+}
+
+int MemEntryImpl::GetAvailableRange(int64 offset, int len, int64* start,
+                                    const CompletionCallback& callback) {
+  if (net_log_.IsLoggingAllEvents()) {
+    net_log_.BeginEvent(
+        net::NetLog::TYPE_SPARSE_GET_RANGE,
+        CreateNetLogSparseOperationCallback(offset, len));
+  }
+  int result = GetAvailableRange(offset, len, start);
+  if (net_log_.IsLoggingAllEvents()) {
+    net_log_.EndEvent(
+        net::NetLog::TYPE_SPARSE_GET_RANGE,
+        CreateNetLogGetAvailableRangeResultCallback(*start, result));
+  }
+  return result;
+}
+
+bool MemEntryImpl::CouldBeSparse() const {
+  DCHECK_EQ(kParentEntry, type());
+  return (children_.get() != NULL);
+}
+
+int MemEntryImpl::ReadyForSparseIO(const CompletionCallback& callback) {
+  return net::OK;
+}
+
+// ------------------------------------------------------------------------
+
+MemEntryImpl::~MemEntryImpl() {
+  for (int i = 0; i < NUM_STREAMS; i++)
+    backend_->ModifyStorageSize(data_size_[i], 0);
+  backend_->ModifyStorageSize(static_cast<int32>(key_.size()), 0);
+  net_log_.EndEvent(net::NetLog::TYPE_DISK_CACHE_MEM_ENTRY_IMPL);
+}
+
+int MemEntryImpl::InternalReadData(int index, int offset, IOBuffer* buf,
+                                   int buf_len) {
+  DCHECK(type() == kParentEntry || index == kSparseData);
+
+  if (index < 0 || index >= NUM_STREAMS)
+    return net::ERR_INVALID_ARGUMENT;
+
+  int entry_size = GetDataSize(index);
+  if (offset >= entry_size || offset < 0 || !buf_len)
+    return 0;
+
+  if (buf_len < 0)
+    return net::ERR_INVALID_ARGUMENT;
+
+  if (offset + buf_len > entry_size)
+    buf_len = entry_size - offset;
+
+  UpdateRank(false);
+
+  memcpy(buf->data(), &(data_[index])[offset], buf_len);
+  return buf_len;
+}
+
+int MemEntryImpl::InternalWriteData(int index, int offset, IOBuffer* buf,
+                                    int buf_len, bool truncate) {
+  DCHECK(type() == kParentEntry || index == kSparseData);
+
+  if (index < 0 || index >= NUM_STREAMS)
+    return net::ERR_INVALID_ARGUMENT;
+
+  if (offset < 0 || buf_len < 0)
+    return net::ERR_INVALID_ARGUMENT;
+
+  int max_file_size = backend_->MaxFileSize();
+
+  // offset of buf_len could be negative numbers.
+  if (offset > max_file_size || buf_len > max_file_size ||
+      offset + buf_len > max_file_size) {
+    return net::ERR_FAILED;
+  }
+
+  // Read the size at this point.
+  int entry_size = GetDataSize(index);
+
+  PrepareTarget(index, offset, buf_len);
+
+  if (entry_size < offset + buf_len) {
+    backend_->ModifyStorageSize(entry_size, offset + buf_len);
+    data_size_[index] = offset + buf_len;
+  } else if (truncate) {
+    if (entry_size > offset + buf_len) {
+      backend_->ModifyStorageSize(entry_size, offset + buf_len);
+      data_size_[index] = offset + buf_len;
+    }
+  }
+
+  UpdateRank(true);
+
+  if (!buf_len)
+    return 0;
+
+  memcpy(&(data_[index])[offset], buf->data(), buf_len);
+  return buf_len;
+}
+
+int MemEntryImpl::InternalReadSparseData(int64 offset, IOBuffer* buf,
+                                         int buf_len) {
+  DCHECK(type() == kParentEntry);
+
+  if (!InitSparseInfo())
+    return net::ERR_CACHE_OPERATION_NOT_SUPPORTED;
+
+  if (offset < 0 || buf_len < 0)
+    return net::ERR_INVALID_ARGUMENT;
+
+  // We will keep using this buffer and adjust the offset in this buffer.
+  scoped_refptr<net::DrainableIOBuffer> io_buf(
+      new net::DrainableIOBuffer(buf, buf_len));
+
+  // Iterate until we have read enough.
+  while (io_buf->BytesRemaining()) {
+    MemEntryImpl* child = OpenChild(offset + io_buf->BytesConsumed(), false);
+
+    // No child present for that offset.
+    if (!child)
+      break;
+
+    // We then need to prepare the child offset and len.
+    int child_offset = ToChildOffset(offset + io_buf->BytesConsumed());
+
+    // If we are trying to read from a position that the child entry has no data
+    // we should stop.
+    if (child_offset < child->child_first_pos_)
+      break;
+    if (net_log_.IsLoggingAllEvents()) {
+      net_log_.BeginEvent(
+          net::NetLog::TYPE_SPARSE_READ_CHILD_DATA,
+          CreateNetLogSparseReadWriteCallback(child->net_log().source(),
+                                              io_buf->BytesRemaining()));
+    }
+    int ret = child->ReadData(kSparseData, child_offset, io_buf.get(),
+                              io_buf->BytesRemaining(), CompletionCallback());
+    if (net_log_.IsLoggingAllEvents()) {
+      net_log_.EndEventWithNetErrorCode(
+          net::NetLog::TYPE_SPARSE_READ_CHILD_DATA, ret);
+    }
+
+    // If we encounter an error in one entry, return immediately.
+    if (ret < 0)
+      return ret;
+    else if (ret == 0)
+      break;
+
+    // Increment the counter by number of bytes read in the child entry.
+    io_buf->DidConsume(ret);
+  }
+
+  UpdateRank(false);
+
+  return io_buf->BytesConsumed();
+}
+
+int MemEntryImpl::InternalWriteSparseData(int64 offset, IOBuffer* buf,
+                                          int buf_len) {
+  DCHECK(type() == kParentEntry);
+
+  if (!InitSparseInfo())
+    return net::ERR_CACHE_OPERATION_NOT_SUPPORTED;
+
+  if (offset < 0 || buf_len < 0)
+    return net::ERR_INVALID_ARGUMENT;
+
+  scoped_refptr<net::DrainableIOBuffer> io_buf(
+      new net::DrainableIOBuffer(buf, buf_len));
+
+  // This loop walks through child entries continuously starting from |offset|
+  // and writes blocks of data (of maximum size kMaxSparseEntrySize) into each
+  // child entry until all |buf_len| bytes are written. The write operation can
+  // start in the middle of an entry.
+  while (io_buf->BytesRemaining()) {
+    MemEntryImpl* child = OpenChild(offset + io_buf->BytesConsumed(), true);
+    int child_offset = ToChildOffset(offset + io_buf->BytesConsumed());
+
+    // Find the right amount to write, this evaluates the remaining bytes to
+    // write and remaining capacity of this child entry.
+    int write_len = std::min(static_cast<int>(io_buf->BytesRemaining()),
+                             kMaxSparseEntrySize - child_offset);
+
+    // Keep a record of the last byte position (exclusive) in the child.
+    int data_size = child->GetDataSize(kSparseData);
+
+    if (net_log_.IsLoggingAllEvents()) {
+      net_log_.BeginEvent(
+          net::NetLog::TYPE_SPARSE_WRITE_CHILD_DATA,
+          CreateNetLogSparseReadWriteCallback(child->net_log().source(),
+                                              write_len));
+    }
+
+    // Always writes to the child entry. This operation may overwrite data
+    // previously written.
+    // TODO(hclam): if there is data in the entry and this write is not
+    // continuous we may want to discard this write.
+    int ret = child->WriteData(kSparseData, child_offset, io_buf.get(),
+                               write_len, CompletionCallback(), true);
+    if (net_log_.IsLoggingAllEvents()) {
+      net_log_.EndEventWithNetErrorCode(
+          net::NetLog::TYPE_SPARSE_WRITE_CHILD_DATA, ret);
+    }
+    if (ret < 0)
+      return ret;
+    else if (ret == 0)
+      break;
+
+    // Keep a record of the first byte position in the child if the write was
+    // not aligned nor continuous. This is to enable witting to the middle
+    // of an entry and still keep track of data off the aligned edge.
+    if (data_size != child_offset)
+      child->child_first_pos_ = child_offset;
+
+    // Adjust the offset in the IO buffer.
+    io_buf->DidConsume(ret);
+  }
+
+  UpdateRank(true);
+
+  return io_buf->BytesConsumed();
+}
+
+int MemEntryImpl::GetAvailableRange(int64 offset, int len, int64* start) {
+  DCHECK(type() == kParentEntry);
+  DCHECK(start);
+
+  if (!InitSparseInfo())
+    return net::ERR_CACHE_OPERATION_NOT_SUPPORTED;
+
+  if (offset < 0 || len < 0 || !start)
+    return net::ERR_INVALID_ARGUMENT;
+
+  MemEntryImpl* current_child = NULL;
+
+  // Find the first child and record the number of empty bytes.
+  int empty = FindNextChild(offset, len, &current_child);
+  if (current_child) {
+    *start = offset + empty;
+    len -= empty;
+
+    // Counts the number of continuous bytes.
+    int continuous = 0;
+
+    // This loop scan for continuous bytes.
+    while (len && current_child) {
+      // Number of bytes available in this child.
+      int data_size = current_child->GetDataSize(kSparseData) -
+                      ToChildOffset(*start + continuous);
+      if (data_size > len)
+        data_size = len;
+
+      // We have found more continuous bytes so increment the count. Also
+      // decrement the length we should scan.
+      continuous += data_size;
+      len -= data_size;
+
+      // If the next child is discontinuous, break the loop.
+      if (FindNextChild(*start + continuous, len, &current_child))
+        break;
+    }
+    return continuous;
+  }
+  *start = offset;
+  return 0;
+}
+
+void MemEntryImpl::PrepareTarget(int index, int offset, int buf_len) {
+  int entry_size = GetDataSize(index);
+
+  if (entry_size >= offset + buf_len)
+    return;  // Not growing the stored data.
+
+  if (static_cast<int>(data_[index].size()) < offset + buf_len)
+    data_[index].resize(offset + buf_len);
+
+  if (offset <= entry_size)
+    return;  // There is no "hole" on the stored data.
+
+  // Cleanup the hole not written by the user. The point is to avoid returning
+  // random stuff later on.
+  memset(&(data_[index])[entry_size], 0, offset - entry_size);
+}
+
+void MemEntryImpl::UpdateRank(bool modified) {
+  Time current = Time::Now();
+  last_used_ = current;
+
+  if (modified)
+    last_modified_ = current;
+
+  if (!doomed_)
+    backend_->UpdateRank(this);
+}
+
+bool MemEntryImpl::InitSparseInfo() {
+  DCHECK(type() == kParentEntry);
+
+  if (!children_.get()) {
+    // If we already have some data in sparse stream but we are being
+    // initialized as a sparse entry, we should fail.
+    if (GetDataSize(kSparseData))
+      return false;
+    children_.reset(new EntryMap());
+
+    // The parent entry stores data for the first block, so save this object to
+    // index 0.
+    (*children_)[0] = this;
+  }
+  return true;
+}
+
+bool MemEntryImpl::InitChildEntry(MemEntryImpl* parent, int child_id,
+                                  net::NetLog* net_log) {
+  DCHECK(!parent_);
+  DCHECK(!child_id_);
+
+  net_log_ = net::BoundNetLog::Make(net_log,
+                                    net::NetLog::SOURCE_MEMORY_CACHE_ENTRY);
+  net_log_.BeginEvent(
+      net::NetLog::TYPE_DISK_CACHE_MEM_ENTRY_IMPL,
+      base::Bind(&NetLogChildEntryCreationCallback, parent, child_id_));
+
+  parent_ = parent;
+  child_id_ = child_id;
+  Time current = Time::Now();
+  last_modified_ = current;
+  last_used_ = current;
+  // Insert this to the backend's ranking list.
+  backend_->InsertIntoRankingList(this);
+  return true;
+}
+
+MemEntryImpl* MemEntryImpl::OpenChild(int64 offset, bool create) {
+  DCHECK(type() == kParentEntry);
+  int index = ToChildIndex(offset);
+  EntryMap::iterator i = children_->find(index);
+  if (i != children_->end()) {
+    return i->second;
+  } else if (create) {
+    MemEntryImpl* child = new MemEntryImpl(backend_);
+    child->InitChildEntry(this, index, net_log_.net_log());
+    (*children_)[index] = child;
+    return child;
+  }
+  return NULL;
+}
+
+int MemEntryImpl::FindNextChild(int64 offset, int len, MemEntryImpl** child) {
+  DCHECK(child);
+  *child = NULL;
+  int scanned_len = 0;
+
+  // This loop tries to find the first existing child.
+  while (scanned_len < len) {
+    // This points to the current offset in the child.
+    int current_child_offset = ToChildOffset(offset + scanned_len);
+    MemEntryImpl* current_child = OpenChild(offset + scanned_len, false);
+    if (current_child) {
+      int child_first_pos = current_child->child_first_pos_;
+
+      // This points to the first byte that we should be reading from, we need
+      // to take care of the filled region and the current offset in the child.
+      int first_pos =  std::max(current_child_offset, child_first_pos);
+
+      // If the first byte position we should read from doesn't exceed the
+      // filled region, we have found the first child.
+      if (first_pos < current_child->GetDataSize(kSparseData)) {
+         *child = current_child;
+
+         // We need to advance the scanned length.
+         scanned_len += first_pos - current_child_offset;
+         break;
+      }
+    }
+    scanned_len += kMaxSparseEntrySize - current_child_offset;
+  }
+  return scanned_len;
+}
+
+void MemEntryImpl::DetachChild(int child_id) {
+  children_->erase(child_id);
+}
+
+}  // namespace disk_cache