cmds/statsd/src/FieldValue.h - platform/frameworks/base - Git at Google

 /*
  * Copyright (C) 2018 The Android Open Source Project
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
  *
  *      http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
 #pragma once

 #include "frameworks/base/cmds/statsd/src/statsd_config.pb.h"
 #include "annotations.h"

 namespace android {
 namespace os {
 namespace statsd {

 class HashableDimensionKey;
 struct Matcher;
 struct Field;
 struct FieldValue;

 const int32_t kMaxLogDepth = 2;
 const int32_t kLastBitMask = 0x80;
 const int32_t kClearLastBitDeco = 0x7f;
 const int32_t kClearAllPositionMatcherMask = 0xffff00ff;

 enum Type { UNKNOWN, INT, LONG, FLOAT, DOUBLE, STRING, STORAGE };

 int32_t getEncodedField(int32_t pos[], int32_t depth, bool includeDepth);

 int32_t encodeMatcherMask(int32_t mask[], int32_t depth);

 // Get the encoded field for a leaf with a [field] number at depth 0;
 inline int32_t getSimpleField(size_t field) {
     return ((int32_t)field << 8 * 2);
 }

 /**
  * Field is a wrapper class for 2 integers that represents the field of a log element in its Atom
  * proto.
  * [mTag]: the atom id.
  * [mField]: encoded path from the root (atom) to leaf.
  *
  * For example:
  * WakeLockStateChanged {
  *    repeated AttributionNode = 1;
  *    int state = 2;
  *    string tag = 3;
  * }
  * Read from logd, the items are structured as below:
  * [[[1000, "tag"], [2000, "tag2"],], 2,"hello"]
  *
  * When we read through the list, we will encode each field in a 32bit integer.
  * 8bit segments   |--------|--------|--------|--------|
  *                    Depth   field0 [L]field1 [L]field1
  *
  *  The first 8 bits are the depth of the field. for example, the uid 1000 has depth 2.
  *  The following 3 8-bit are for the item's position at each level.
  *  The first bit of each 8bits field is reserved to mark if the item is the last item at that level
  *  this is to make matching easier later.
  *
  *  The above wakelock event is translated into FieldValue pairs.
  *  0x02010101->1000
  *  0x02010182->tag
  *  0x02018201->2000
  *  0x02018282->tag2
  *  0x00020000->2
  *  0x00030000->"hello"
  *
  *  This encoding is the building block for the later operations.
  *  Please see the definition for Matcher below to see how the matching is done.
  */
 struct Field {
 private:
     int32_t mTag;
     int32_t mField;

 public:
     Field() {}

     Field(int32_t tag, int32_t pos[], int32_t depth) : mTag(tag) {
         mField = getEncodedField(pos, depth, true);
     }

     Field(const Field& from) : mTag(from.getTag()), mField(from.getField()) {
     }

     Field(int32_t tag, int32_t field) : mTag(tag), mField(field){};

     inline void setField(int32_t field) {
         mField = field;
     }

     inline void setTag(int32_t tag) {
         mTag = tag;
     }

     inline void decorateLastPos(int32_t depth) {
         int32_t mask = kLastBitMask << 8 * (kMaxLogDepth - depth);
         mField |= mask;
     }

     inline int32_t getTag() const {
         return mTag;
     }

     inline int32_t getDepth() const {
         return (mField >> 24);
     }

     inline int32_t getPath(int32_t depth) const {
         if (depth > 2 || depth < 0) return 0;

         int32_t field = (mField & 0x00ffffff);
         int32_t mask = 0xffffffff;
         return (field & (mask << 8 * (kMaxLogDepth - depth)));
     }

     inline int32_t getPrefix(int32_t depth) const {
         if (depth == 0) return 0;
         return getPath(depth - 1);
     }

     inline int32_t getField() const {
         return mField;
     }

     inline int32_t getRawPosAtDepth(int32_t depth) const {
         int32_t field = (mField & 0x00ffffff);
         int32_t shift = 8 * (kMaxLogDepth - depth);
         int32_t mask = 0xff << shift;

         return (field & mask) >> shift;
     }

     inline int32_t getPosAtDepth(int32_t depth) const {
         return getRawPosAtDepth(depth) & kClearLastBitDeco;
     }

     // Check if the first bit of the 8-bit segment for depth is 1
     inline bool isLastPos(int32_t depth) const {
         int32_t field = (mField & 0x00ffffff);
         int32_t mask = kLastBitMask << 8 * (kMaxLogDepth - depth);
         return (field & mask) != 0;
     }

     // if the 8-bit segment is all 0's
     inline bool isAnyPosMatcher(int32_t depth) const {
         return getDepth() >= depth && getRawPosAtDepth(depth) == 0;
     }
     // if the 8bit is 0x80 (1000 0000)
     inline bool isLastPosMatcher(int32_t depth) const {
         return getDepth() >= depth && getRawPosAtDepth(depth) == kLastBitMask;
     }

     inline bool operator==(const Field& that) const {
         return mTag == that.getTag() && mField == that.getField();
     };

     inline bool operator!=(const Field& that) const {
         return mTag != that.getTag() || mField != that.getField();
     };

     bool operator<(const Field& that) const {
         if (mTag != that.getTag()) {
             return mTag < that.getTag();
         }

         if (mField != that.getField()) {
             return mField < that.getField();
         }

         return false;
     }

     bool matches(const Matcher& that) const;
 };

 /**
  * Matcher represents a leaf matcher in the FieldMatcher in statsd_config.
  *
  * It contains all information needed to match one or more leaf node.
  * All information is encoded in a Field(2 ints) and a bit mask(1 int).
  *
  * For example, to match the first/any/last uid field in attribution chain in Atom 10,
  * we have the following FieldMatcher in statsd_config
  *    FieldMatcher {
  *        field:10
  *         FieldMatcher {
  *              field:1
  *              position: any/last/first
  *              FieldMatcher {
  *                  field:1
  *              }
  *          }
  *     }
  *
  * We translate the FieldMatcher into a Field, and mask
  * First: [Matcher Field] 0x02010101  [Mask]0xff7f7f7f
  * Last:  [Matcher Field] 0x02018001  [Mask]0xff7f807f
  * Any:   [Matcher Field] 0x02010001  [Mask]0xff7f007f
  * All:   [Matcher Field] 0x02010001  [Mask]0xff7f7f7f
  *
  * [To match a log Field with a Matcher] we apply the bit mask to the log Field and check if
  * the result is equal to the Matcher Field. That's a bit wise AND operation + check if 2 ints are
  * equal. Nothing can beat the performance of this matching algorithm.
  *
  * TODO(b/110561213): ADD EXAMPLE HERE.
  */
 struct Matcher {
     Matcher(const Field& matcher, int32_t mask) : mMatcher(matcher), mMask(mask){};

     const Field mMatcher;
     const int32_t mMask;

     inline const Field& getMatcher() const {
         return mMatcher;
     }

     inline int32_t getMask() const {
         return mMask;
     }

     inline int32_t getRawMaskAtDepth(int32_t depth) const {
         int32_t field = (mMask & 0x00ffffff);
         int32_t shift = 8 * (kMaxLogDepth - depth);
         int32_t mask = 0xff << shift;

         return (field & mask) >> shift;
     }

     bool hasAllPositionMatcher() const {
         return mMatcher.getDepth() == 2 && getRawMaskAtDepth(1) == 0x7f;
     }

     bool hasAnyPositionMatcher(int* prefix) const {
         if (mMatcher.getDepth() == 2 && mMatcher.getRawPosAtDepth(1) == 0) {
             (*prefix) = mMatcher.getPrefix(1);
             return true;
         }
         return false;
     }

     inline bool operator!=(const Matcher& that) const {
         return mMatcher != that.getMatcher() || mMask != that.getMask();
     }

     inline bool operator==(const Matcher& that) const {
         return mMatcher == that.mMatcher && mMask == that.mMask;
     }
 };

 inline Matcher getSimpleMatcher(int32_t tag, size_t field) {
     return Matcher(Field(tag, getSimpleField(field)), 0xff7f0000);
 }

 inline Matcher getFirstUidMatcher(int32_t atomId) {
     int32_t pos[] = {1, 1, 1};
     return Matcher(Field(atomId, pos, 2), 0xff7f7f7f);
 }

 /**
  * A wrapper for a union type to contain multiple types of values.
  *
  */
 struct Value {
     Value() : type(UNKNOWN) {}

     Value(int32_t v) {
         int_value = v;
         type = INT;
     }

     Value(int64_t v) {
         long_value = v;
         type = LONG;
     }

     Value(float v) {
         float_value = v;
         type = FLOAT;
     }

     Value(double v) {
         double_value = v;
         type = DOUBLE;
     }

     Value(const std::string& v) {
         str_value = v;
         type = STRING;
     }

     Value(const std::vector<uint8_t>& v) {
         storage_value = v;
         type = STORAGE;
     }

     void setInt(int32_t v) {
         int_value = v;
         type = INT;
     }

     void setLong(int64_t v) {
         long_value = v;
         type = LONG;
     }

     void setFloat(float v) {
         float_value = v;
         type = FLOAT;
     }

     void setDouble(double v) {
         double_value = v;
         type = DOUBLE;
     }

     union {
         int32_t int_value;
         int64_t long_value;
         float float_value;
         double double_value;
     };
     std::string str_value;
     std::vector<uint8_t> storage_value;

     Type type;

     std::string toString() const;

     bool isZero() const;

     Type getType() const {
         return type;
     }

     double getDouble() const;

     Value(const Value& from);

     bool operator==(const Value& that) const;
     bool operator!=(const Value& that) const;

     bool operator<(const Value& that) const;
     bool operator>(const Value& that) const;
     bool operator>=(const Value& that) const;
     Value operator-(const Value& that) const;
     Value& operator+=(const Value& that);
     Value& operator=(const Value& that);
 };

 class Annotations {
 public:
     Annotations() {
         setNested(true);  // Nested = true by default
     }

     // This enum stores where particular annotations can be found in the
     // bitmask. Note that these pos do not correspond to annotation ids.
     enum {
         NESTED_POS = 0x0,
         PRIMARY_POS = 0x1,
         EXCLUSIVE_POS = 0x2,
         UID_POS = 0x3
     };

     inline void setNested(bool nested) { setBitmaskAtPos(NESTED_POS, nested); }

     inline void setPrimaryField(bool primary) { setBitmaskAtPos(PRIMARY_POS, primary); }

     inline void setExclusiveState(bool exclusive) { setBitmaskAtPos(EXCLUSIVE_POS, exclusive); }

     inline void setUidField(bool isUid) { setBitmaskAtPos(UID_POS, isUid); }

     // Default value = false
     inline bool isNested() const { return getValueFromBitmask(NESTED_POS); }

     // Default value = false
     inline bool isPrimaryField() const { return getValueFromBitmask(PRIMARY_POS); }

     // Default value = false
     inline bool isExclusiveState() const { return getValueFromBitmask(EXCLUSIVE_POS); }

     // Default value = false
     inline bool isUidField() const { return getValueFromBitmask(UID_POS); }

 private:
     inline void setBitmaskAtPos(int pos, bool value) {
         mBooleanBitmask &= ~(1 << pos); // clear
         mBooleanBitmask |= (value << pos); // set
     }

     inline bool getValueFromBitmask(int pos) const {
         return (mBooleanBitmask >> pos) & 0x1;
     }

     // This is a bitmask over all annotations stored in boolean form. Because
     // there are only 4 booleans, just one byte is required.
     uint8_t mBooleanBitmask = 0;
 };

 /**
  * Represents a log item, or a dimension item (They are essentially the same).
  */
 struct FieldValue {
     FieldValue() {}
     FieldValue(const Field& field, const Value& value) : mField(field), mValue(value) {
     }
     bool operator==(const FieldValue& that) const {
         return mField == that.mField && mValue == that.mValue;
     }
     bool operator!=(const FieldValue& that) const {
         return mField != that.mField || mValue != that.mValue;
     }
     bool operator<(const FieldValue& that) const {
         if (mField != that.mField) {
             return mField < that.mField;
         }

         if (mValue != that.mValue) {
             return mValue < that.mValue;
         }

         return false;
     }

     Field mField;
     Value mValue;
     Annotations mAnnotations;
 };

 bool HasPositionANY(const FieldMatcher& matcher);
 bool HasPositionALL(const FieldMatcher& matcher);

 bool isAttributionUidField(const FieldValue& value);

 /* returns uid if the field is uid field, or -1 if the field is not a uid field */
 int getUidIfExists(const FieldValue& value);

 void translateFieldMatcher(const FieldMatcher& matcher, std::vector<Matcher>* output);

 bool isAttributionUidField(const Field& field, const Value& value);
 bool isUidField(const FieldValue& fieldValue);

 bool equalDimensions(const std::vector<Matcher>& dimension_a,
                      const std::vector<Matcher>& dimension_b);

 // Returns true if dimension_a is a subset of dimension_b.
 bool subsetDimensions(const std::vector<Matcher>& dimension_a,
                       const std::vector<Matcher>& dimension_b);
 }  // namespace statsd
 }  // namespace os
 }  // namespace android
	/*
	* Copyright (C) 2018 The Android Open Source Project
	*
	* Licensed under the Apache License, Version 2.0 (the "License");
	* you may not use this file except in compliance with the License.
	* You may obtain a copy of the License at
	*
	* http://www.apache.org/licenses/LICENSE-2.0
	*
	* Unless required by applicable law or agreed to in writing, software
	* distributed under the License is distributed on an "AS IS" BASIS,
	* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	* See the License for the specific language governing permissions and
	* limitations under the License.
	*/
	#pragma once

	#include "frameworks/base/cmds/statsd/src/statsd_config.pb.h"
	#include "annotations.h"

	namespace android {
	namespace os {
	namespace statsd {

	class HashableDimensionKey;
	struct Matcher;
	struct Field;
	struct FieldValue;

	const int32_t kMaxLogDepth = 2;
	const int32_t kLastBitMask = 0x80;
	const int32_t kClearLastBitDeco = 0x7f;
	const int32_t kClearAllPositionMatcherMask = 0xffff00ff;

	enum Type { UNKNOWN, INT, LONG, FLOAT, DOUBLE, STRING, STORAGE };

	int32_t getEncodedField(int32_t pos[], int32_t depth, bool includeDepth);

	int32_t encodeMatcherMask(int32_t mask[], int32_t depth);

	// Get the encoded field for a leaf with a [field] number at depth 0;
	inline int32_t getSimpleField(size_t field) {
	return ((int32_t)field << 8 * 2);
	}

	/**
	* Field is a wrapper class for 2 integers that represents the field of a log element in its Atom
	* proto.
	* [mTag]: the atom id.
	* [mField]: encoded path from the root (atom) to leaf.
	*
	* For example:
	* WakeLockStateChanged {
	* repeated AttributionNode = 1;
	* int state = 2;
	* string tag = 3;
	* }
	* Read from logd, the items are structured as below:
	* [[[1000, "tag"], [2000, "tag2"],], 2,"hello"]
	*
	* When we read through the list, we will encode each field in a 32bit integer.
	* 8bit segments \|--------\|--------\|--------\|--------\|
	* Depth field0 [L]field1 [L]field1
	*
	* The first 8 bits are the depth of the field. for example, the uid 1000 has depth 2.
	* The following 3 8-bit are for the item's position at each level.
	* The first bit of each 8bits field is reserved to mark if the item is the last item at that level
	* this is to make matching easier later.
	*
	* The above wakelock event is translated into FieldValue pairs.
	* 0x02010101->1000
	* 0x02010182->tag
	* 0x02018201->2000
	* 0x02018282->tag2
	* 0x00020000->2
	* 0x00030000->"hello"
	*
	* This encoding is the building block for the later operations.
	* Please see the definition for Matcher below to see how the matching is done.
	*/
	struct Field {
	private:
	int32_t mTag;
	int32_t mField;

	public:
	Field() {}

	Field(int32_t tag, int32_t pos[], int32_t depth) : mTag(tag) {
	mField = getEncodedField(pos, depth, true);
	}

	Field(const Field& from) : mTag(from.getTag()), mField(from.getField()) {
	}

	Field(int32_t tag, int32_t field) : mTag(tag), mField(field){};

	inline void setField(int32_t field) {
	mField = field;
	}

	inline void setTag(int32_t tag) {
	mTag = tag;
	}

	inline void decorateLastPos(int32_t depth) {
	int32_t mask = kLastBitMask << 8 * (kMaxLogDepth - depth);
	mField \|= mask;
	}

	inline int32_t getTag() const {
	return mTag;
	}

	inline int32_t getDepth() const {
	return (mField >> 24);
	}

	inline int32_t getPath(int32_t depth) const {
	if (depth > 2 \|\| depth < 0) return 0;

	int32_t field = (mField & 0x00ffffff);
	int32_t mask = 0xffffffff;
	return (field & (mask << 8 * (kMaxLogDepth - depth)));
	}

	inline int32_t getPrefix(int32_t depth) const {
	if (depth == 0) return 0;
	return getPath(depth - 1);
	}

	inline int32_t getField() const {
	return mField;
	}

	inline int32_t getRawPosAtDepth(int32_t depth) const {
	int32_t field = (mField & 0x00ffffff);
	int32_t shift = 8 * (kMaxLogDepth - depth);
	int32_t mask = 0xff << shift;

	return (field & mask) >> shift;
	}

	inline int32_t getPosAtDepth(int32_t depth) const {
	return getRawPosAtDepth(depth) & kClearLastBitDeco;
	}

	// Check if the first bit of the 8-bit segment for depth is 1
	inline bool isLastPos(int32_t depth) const {
	int32_t field = (mField & 0x00ffffff);
	int32_t mask = kLastBitMask << 8 * (kMaxLogDepth - depth);
	return (field & mask) != 0;
	}

	// if the 8-bit segment is all 0's
	inline bool isAnyPosMatcher(int32_t depth) const {
	return getDepth() >= depth && getRawPosAtDepth(depth) == 0;
	}
	// if the 8bit is 0x80 (1000 0000)
	inline bool isLastPosMatcher(int32_t depth) const {
	return getDepth() >= depth && getRawPosAtDepth(depth) == kLastBitMask;
	}

	inline bool operator==(const Field& that) const {
	return mTag == that.getTag() && mField == that.getField();
	};

	inline bool operator!=(const Field& that) const {
	return mTag != that.getTag() \|\| mField != that.getField();
	};

	bool operator<(const Field& that) const {
	if (mTag != that.getTag()) {
	return mTag < that.getTag();
	}

	if (mField != that.getField()) {
	return mField < that.getField();
	}

	return false;
	}

	bool matches(const Matcher& that) const;
	};

	/**
	* Matcher represents a leaf matcher in the FieldMatcher in statsd_config.
	*
	* It contains all information needed to match one or more leaf node.
	* All information is encoded in a Field(2 ints) and a bit mask(1 int).
	*
	* For example, to match the first/any/last uid field in attribution chain in Atom 10,
	* we have the following FieldMatcher in statsd_config
	* FieldMatcher {
	* field:10
	* FieldMatcher {
	* field:1
	* position: any/last/first
	* FieldMatcher {
	* field:1
	* }
	* }
	* }
	*
	* We translate the FieldMatcher into a Field, and mask
	* First: [Matcher Field] 0x02010101 [Mask]0xff7f7f7f
	* Last: [Matcher Field] 0x02018001 [Mask]0xff7f807f
	* Any: [Matcher Field] 0x02010001 [Mask]0xff7f007f
	* All: [Matcher Field] 0x02010001 [Mask]0xff7f7f7f
	*
	* [To match a log Field with a Matcher] we apply the bit mask to the log Field and check if
	* the result is equal to the Matcher Field. That's a bit wise AND operation + check if 2 ints are
	* equal. Nothing can beat the performance of this matching algorithm.
	*
	* TODO(b/110561213): ADD EXAMPLE HERE.
	*/
	struct Matcher {
	Matcher(const Field& matcher, int32_t mask) : mMatcher(matcher), mMask(mask){};

	const Field mMatcher;
	const int32_t mMask;

	inline const Field& getMatcher() const {
	return mMatcher;
	}

	inline int32_t getMask() const {
	return mMask;
	}

	inline int32_t getRawMaskAtDepth(int32_t depth) const {
	int32_t field = (mMask & 0x00ffffff);
	int32_t shift = 8 * (kMaxLogDepth - depth);
	int32_t mask = 0xff << shift;

	return (field & mask) >> shift;
	}

	bool hasAllPositionMatcher() const {
	return mMatcher.getDepth() == 2 && getRawMaskAtDepth(1) == 0x7f;
	}

	bool hasAnyPositionMatcher(int* prefix) const {
	if (mMatcher.getDepth() == 2 && mMatcher.getRawPosAtDepth(1) == 0) {
	(*prefix) = mMatcher.getPrefix(1);
	return true;
	}
	return false;
	}

	inline bool operator!=(const Matcher& that) const {
	return mMatcher != that.getMatcher() \|\| mMask != that.getMask();
	}

	inline bool operator==(const Matcher& that) const {
	return mMatcher == that.mMatcher && mMask == that.mMask;
	}
	};

	inline Matcher getSimpleMatcher(int32_t tag, size_t field) {
	return Matcher(Field(tag, getSimpleField(field)), 0xff7f0000);
	}

	inline Matcher getFirstUidMatcher(int32_t atomId) {
	int32_t pos[] = {1, 1, 1};
	return Matcher(Field(atomId, pos, 2), 0xff7f7f7f);
	}

	/**
	* A wrapper for a union type to contain multiple types of values.
	*
	*/
	struct Value {
	Value() : type(UNKNOWN) {}

	Value(int32_t v) {
	int_value = v;
	type = INT;
	}

	Value(int64_t v) {
	long_value = v;
	type = LONG;
	}

	Value(float v) {
	float_value = v;
	type = FLOAT;
	}

	Value(double v) {
	double_value = v;
	type = DOUBLE;
	}

	Value(const std::string& v) {
	str_value = v;
	type = STRING;
	}

	Value(const std::vector<uint8_t>& v) {
	storage_value = v;
	type = STORAGE;
	}

	void setInt(int32_t v) {
	int_value = v;
	type = INT;
	}

	void setLong(int64_t v) {
	long_value = v;
	type = LONG;
	}

	void setFloat(float v) {
	float_value = v;
	type = FLOAT;
	}

	void setDouble(double v) {
	double_value = v;
	type = DOUBLE;
	}

	union {
	int32_t int_value;
	int64_t long_value;
	float float_value;
	double double_value;
	};
	std::string str_value;
	std::vector<uint8_t> storage_value;

	Type type;

	std::string toString() const;

	bool isZero() const;

	Type getType() const {
	return type;
	}

	double getDouble() const;

	Value(const Value& from);

	bool operator==(const Value& that) const;
	bool operator!=(const Value& that) const;

	bool operator<(const Value& that) const;
	bool operator>(const Value& that) const;
	bool operator>=(const Value& that) const;
	Value operator-(const Value& that) const;
	Value& operator+=(const Value& that);
	Value& operator=(const Value& that);
	};

	class Annotations {
	public:
	Annotations() {
	setNested(true); // Nested = true by default
	}

	// This enum stores where particular annotations can be found in the
	// bitmask. Note that these pos do not correspond to annotation ids.
	enum {
	NESTED_POS = 0x0,
	PRIMARY_POS = 0x1,
	EXCLUSIVE_POS = 0x2,
	UID_POS = 0x3
	};

	inline void setNested(bool nested) { setBitmaskAtPos(NESTED_POS, nested); }

	inline void setPrimaryField(bool primary) { setBitmaskAtPos(PRIMARY_POS, primary); }

	inline void setExclusiveState(bool exclusive) { setBitmaskAtPos(EXCLUSIVE_POS, exclusive); }

	inline void setUidField(bool isUid) { setBitmaskAtPos(UID_POS, isUid); }

	// Default value = false
	inline bool isNested() const { return getValueFromBitmask(NESTED_POS); }

	// Default value = false
	inline bool isPrimaryField() const { return getValueFromBitmask(PRIMARY_POS); }

	// Default value = false
	inline bool isExclusiveState() const { return getValueFromBitmask(EXCLUSIVE_POS); }

	// Default value = false
	inline bool isUidField() const { return getValueFromBitmask(UID_POS); }

	private:
	inline void setBitmaskAtPos(int pos, bool value) {
	mBooleanBitmask &= ~(1 << pos); // clear
	mBooleanBitmask \|= (value << pos); // set
	}

	inline bool getValueFromBitmask(int pos) const {
	return (mBooleanBitmask >> pos) & 0x1;
	}

	// This is a bitmask over all annotations stored in boolean form. Because
	// there are only 4 booleans, just one byte is required.
	uint8_t mBooleanBitmask = 0;
	};

	/**
	* Represents a log item, or a dimension item (They are essentially the same).
	*/
	struct FieldValue {
	FieldValue() {}
	FieldValue(const Field& field, const Value& value) : mField(field), mValue(value) {
	}
	bool operator==(const FieldValue& that) const {
	return mField == that.mField && mValue == that.mValue;
	}
	bool operator!=(const FieldValue& that) const {
	return mField != that.mField \|\| mValue != that.mValue;
	}
	bool operator<(const FieldValue& that) const {
	if (mField != that.mField) {
	return mField < that.mField;
	}

	if (mValue != that.mValue) {
	return mValue < that.mValue;
	}

	return false;
	}

	Field mField;
	Value mValue;
	Annotations mAnnotations;
	};

	bool HasPositionANY(const FieldMatcher& matcher);
	bool HasPositionALL(const FieldMatcher& matcher);

	bool isAttributionUidField(const FieldValue& value);

	/* returns uid if the field is uid field, or -1 if the field is not a uid field */
	int getUidIfExists(const FieldValue& value);

	void translateFieldMatcher(const FieldMatcher& matcher, std::vector<Matcher>* output);

	bool isAttributionUidField(const Field& field, const Value& value);
	bool isUidField(const FieldValue& fieldValue);

	bool equalDimensions(const std::vector<Matcher>& dimension_a,
	const std::vector<Matcher>& dimension_b);

	// Returns true if dimension_a is a subset of dimension_b.
	bool subsetDimensions(const std::vector<Matcher>& dimension_a,
	const std::vector<Matcher>& dimension_b);
	} // namespace statsd
	} // namespace os
	} // namespace android