dart::kernel::MetadataHelper Class Reference

#include <kernel_translation_helper.h>

Inheritance diagram for dart::kernel::MetadataHelper:

Public Member Functions
	MetadataHelper (KernelReaderHelper *helper, const char *tag, bool precompiler_only)

Protected Member Functions
intptr_t	FindMetadataMapping (intptr_t node_offset)
intptr_t	GetNextMetadataPayloadOffset (intptr_t node_offset)
intptr_t	GetComponentMetadataPayloadOffset ()

Protected Attributes
KernelReaderHelper *	helper_
TranslationHelper &	translation_helper_

Detailed Description

Definition at line 937 of file kernel_translation_helper.h.

Constructor & Destructor Documentation

MetadataHelper()

dart::kernel::MetadataHelper::MetadataHelper	(	KernelReaderHelper *	helper,
		const char *	tag,
		bool	precompiler_only
	)

Definition at line 1586 of file kernel_translation_helper.cc.

    : helper_(helper),
      translation_helper_(helper->translation_helper_),
      tag_(tag),
      mappings_scanned_(false),
      precompiler_only_(precompiler_only),
      mappings_offset_(0),
      mappings_num_(0),
      last_node_offset_(0),
      last_mapping_index_(0) {}

Member Function Documentation

FindMetadataMapping()

intptr_t dart::kernel::MetadataHelper::FindMetadataMapping ( intptr_t  node_offset )

protected

Definition at line 1651 of file kernel_translation_helper.cc.

                                                                 {
  const intptr_t kUInt32Size = 4;
  ASSERT(mappings_num_ > 0);
 
  Reader reader(H.metadata_mappings());
 
  intptr_t left = 0;
  intptr_t right = mappings_num_ - 1;
  while (left < right) {
    intptr_t mid = ((right - left) / 2) + left;
    intptr_t mid_node_offset =
        reader.ReadUInt32At(mappings_offset_ + mid * 2 * kUInt32Size);
 
    if (node_offset < mid_node_offset) {
      right = mid - 1;
    } else if (node_offset > mid_node_offset) {
      left = mid + 1;
    } else {
      return mid;  // Exact match found.
    }
  }
  ASSERT((0 <= left) && (left <= mappings_num_));
 
  // Approximate match is found. Make sure it has an offset greater or equal
  // to the given node offset.
  if (left < mappings_num_) {
    intptr_t found_node_offset =
        reader.ReadUInt32At(mappings_offset_ + left * 2 * kUInt32Size);
 
    if (found_node_offset < node_offset) {
      ++left;
    }
  }
  ASSERT((left == mappings_num_) ||
         static_cast<intptr_t>(reader.ReadUInt32At(
             mappings_offset_ + left * 2 * kUInt32Size)) >= node_offset);
 
  return left;
}

GetComponentMetadataPayloadOffset()

intptr_t dart::kernel::MetadataHelper::GetComponentMetadataPayloadOffset ( )

protected

Definition at line 1737 of file kernel_translation_helper.cc.

                                                           {
  const intptr_t kComponentNodeOffset = 0;
  return GetNextMetadataPayloadOffset(kComponentNodeOffset -
                                      helper_->data_program_offset_);
}

GetNextMetadataPayloadOffset()

intptr_t dart::kernel::MetadataHelper::GetNextMetadataPayloadOffset ( intptr_t  node_offset )

protected

Definition at line 1691 of file kernel_translation_helper.cc.

                                                                          {
  if (!mappings_scanned_) {
    ScanMetadataMappings();
    mappings_scanned_ = true;
  }
 
  if (mappings_num_ == 0) {
    return -1;  // No metadata.
  }
 
  node_offset += helper_->data_program_offset_;
 
  // Nodes are parsed in linear order most of the time, so do the search
  // only if looking back.
  if (node_offset < last_node_offset_) {
    last_mapping_index_ = FindMetadataMapping(node_offset);
  }
 
  intptr_t index = last_mapping_index_;
  intptr_t mapping_node_offset = 0;
  intptr_t mapping_md_offset = -1;
 
  Reader reader(H.metadata_mappings());
  const intptr_t kUInt32Size = 4;
  reader.set_offset(mappings_offset_ + index * 2 * kUInt32Size);
 
  for (; index < mappings_num_; ++index) {
    mapping_node_offset = reader.ReadUInt32();
    mapping_md_offset = reader.ReadUInt32();
 
    if (mapping_node_offset >= node_offset) {
      break;
    }
  }
 
  last_mapping_index_ = index;
  last_node_offset_ = node_offset;
 
  if ((index < mappings_num_) && (mapping_node_offset == node_offset)) {
    ASSERT(mapping_md_offset >= 0);
    return mapping_md_offset;
  } else {
    return -1;
  }
}

Member Data Documentation

helper_

KernelReaderHelper* dart::kernel::MetadataHelper::helper_

protected

Definition at line 959 of file kernel_translation_helper.h.

translation_helper_

TranslationHelper& dart::kernel::MetadataHelper::translation_helper_

protected

Definition at line 960 of file kernel_translation_helper.h.

---

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

• third_party/dart-lang/sdk/runtime/vm/compiler/frontend/kernel_translation_helper.h
• third_party/dart-lang/sdk/runtime/vm/compiler/frontend/kernel_translation_helper.cc