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/*
* 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.
*/
package android.util.proto;
import android.annotation.TestApi;
/**
* Abstract base class for both protobuf streams.
*
* Contains a set of useful constants and methods used by both
* ProtoOutputStream and ProtoInputStream
*
* @hide
*/
@TestApi
public abstract class ProtoStream {
public static final int FIELD_ID_SHIFT = 3;
public static final int WIRE_TYPE_MASK = (1 << FIELD_ID_SHIFT) - 1;
public static final int FIELD_ID_MASK = ~WIRE_TYPE_MASK;
public static final int WIRE_TYPE_VARINT = 0;
public static final int WIRE_TYPE_FIXED64 = 1;
public static final int WIRE_TYPE_LENGTH_DELIMITED = 2;
public static final int WIRE_TYPE_START_GROUP = 3;
public static final int WIRE_TYPE_END_GROUP = 4;
public static final int WIRE_TYPE_FIXED32 = 5;
/**
* Position of the field type in a (long) fieldId.
*/
public static final int FIELD_TYPE_SHIFT = 32;
/**
* Mask for the field types stored in a fieldId. Leaves a whole
* byte for future expansion, even though there are currently only 17 types.
*/
public static final long FIELD_TYPE_MASK = 0x0ffL << FIELD_TYPE_SHIFT;
public static final long FIELD_TYPE_UNKNOWN = 0;
/**
* The types are copied from external/protobuf/src/google/protobuf/descriptor.h directly,
* so no extra mapping needs to be maintained in this case.
*/
public static final long FIELD_TYPE_DOUBLE = 1L << FIELD_TYPE_SHIFT;
public static final long FIELD_TYPE_FLOAT = 2L << FIELD_TYPE_SHIFT;
public static final long FIELD_TYPE_INT64 = 3L << FIELD_TYPE_SHIFT;
public static final long FIELD_TYPE_UINT64 = 4L << FIELD_TYPE_SHIFT;
public static final long FIELD_TYPE_INT32 = 5L << FIELD_TYPE_SHIFT;
public static final long FIELD_TYPE_FIXED64 = 6L << FIELD_TYPE_SHIFT;
public static final long FIELD_TYPE_FIXED32 = 7L << FIELD_TYPE_SHIFT;
public static final long FIELD_TYPE_BOOL = 8L << FIELD_TYPE_SHIFT;
public static final long FIELD_TYPE_STRING = 9L << FIELD_TYPE_SHIFT;
// public static final long FIELD_TYPE_GROUP = 10L << FIELD_TYPE_SHIFT; // Deprecated.
public static final long FIELD_TYPE_MESSAGE = 11L << FIELD_TYPE_SHIFT;
public static final long FIELD_TYPE_BYTES = 12L << FIELD_TYPE_SHIFT;
public static final long FIELD_TYPE_UINT32 = 13L << FIELD_TYPE_SHIFT;
public static final long FIELD_TYPE_ENUM = 14L << FIELD_TYPE_SHIFT;
public static final long FIELD_TYPE_SFIXED32 = 15L << FIELD_TYPE_SHIFT;
public static final long FIELD_TYPE_SFIXED64 = 16L << FIELD_TYPE_SHIFT;
public static final long FIELD_TYPE_SINT32 = 17L << FIELD_TYPE_SHIFT;
public static final long FIELD_TYPE_SINT64 = 18L << FIELD_TYPE_SHIFT;
protected static final String[] FIELD_TYPE_NAMES = new String[]{
"Double",
"Float",
"Int64",
"UInt64",
"Int32",
"Fixed64",
"Fixed32",
"Bool",
"String",
"Group", // This field is deprecated but reserved here for indexing.
"Message",
"Bytes",
"UInt32",
"Enum",
"SFixed32",
"SFixed64",
"SInt32",
"SInt64",
};
//
// FieldId flags for whether the field is single, repeated or packed.
//
public static final int FIELD_COUNT_SHIFT = 40;
public static final long FIELD_COUNT_MASK = 0x0fL << FIELD_COUNT_SHIFT;
public static final long FIELD_COUNT_UNKNOWN = 0;
public static final long FIELD_COUNT_SINGLE = 1L << FIELD_COUNT_SHIFT;
public static final long FIELD_COUNT_REPEATED = 2L << FIELD_COUNT_SHIFT;
public static final long FIELD_COUNT_PACKED = 5L << FIELD_COUNT_SHIFT;
/**
* Get the developer-usable name of a field type.
*/
public static String getFieldTypeString(long fieldType) {
int index = ((int) ((fieldType & FIELD_TYPE_MASK) >>> FIELD_TYPE_SHIFT)) - 1;
if (index >= 0 && index < FIELD_TYPE_NAMES.length) {
return FIELD_TYPE_NAMES[index];
} else {
return null;
}
}
/**
* Get the developer-usable name of a field count.
*/
public static String getFieldCountString(long fieldCount) {
if (fieldCount == FIELD_COUNT_SINGLE) {
return "";
} else if (fieldCount == FIELD_COUNT_REPEATED) {
return "Repeated";
} else if (fieldCount == FIELD_COUNT_PACKED) {
return "Packed";
} else {
return null;
}
}
/**
* Get the developer-usable name of a wire type.
*/
public static String getWireTypeString(int wireType) {
switch (wireType) {
case WIRE_TYPE_VARINT:
return "Varint";
case WIRE_TYPE_FIXED64:
return "Fixed64";
case WIRE_TYPE_LENGTH_DELIMITED:
return "Length Delimited";
case WIRE_TYPE_START_GROUP:
return "Start Group";
case WIRE_TYPE_END_GROUP:
return "End Group";
case WIRE_TYPE_FIXED32:
return "Fixed32";
default:
return null;
}
}
/**
* Get a debug string for a fieldId.
*/
public static String getFieldIdString(long fieldId) {
final long fieldCount = fieldId & FIELD_COUNT_MASK;
String countString = getFieldCountString(fieldCount);
if (countString == null) {
countString = "fieldCount=" + fieldCount;
}
if (countString.length() > 0) {
countString += " ";
}
final long fieldType = fieldId & FIELD_TYPE_MASK;
String typeString = getFieldTypeString(fieldType);
if (typeString == null) {
typeString = "fieldType=" + fieldType;
}
return countString + typeString + " tag=" + ((int) fieldId)
+ " fieldId=0x" + Long.toHexString(fieldId);
}
/**
* Combine a fieldId (the field keys in the proto file) and the field flags.
* Mostly useful for testing because the generated code contains the fieldId
* constants.
*/
public static long makeFieldId(int id, long fieldFlags) {
return fieldFlags | (((long) id) & 0x0ffffffffL);
}
//
// Child objects
//
/**
* Make a token.
* Bits 61-63 - tag size (So we can go backwards later if the object had not data)
* - 3 bits, max value 7, max value needed 5
* Bit 60 - true if the object is repeated (lets us require endObject or endRepeatedObject)
* Bits 59-51 - depth (For error checking)
* - 9 bits, max value 512, when checking, value is masked (if we really
* are more than 512 levels deep)
* Bits 32-50 - objectId (For error checking)
* - 19 bits, max value 524,288. that's a lot of objects. IDs will wrap
* because of the overflow, and only the tokens are compared.
* Bits 0-31 - offset of interest for the object.
*/
public static long makeToken(int tagSize, boolean repeated, int depth, int objectId,
int offset) {
return ((0x07L & (long) tagSize) << 61)
| (repeated ? (1L << 60) : 0)
| (0x01ffL & (long) depth) << 51
| (0x07ffffL & (long) objectId) << 32
| (0x0ffffffffL & (long) offset);
}
/**
* Get the encoded tag size from the token.
*/
public static int getTagSizeFromToken(long token) {
return (int) (0x7 & (token >> 61));
}
/**
* Get whether this is a call to startObject (false) or startRepeatedObject (true).
*/
public static boolean getRepeatedFromToken(long token) {
return (0x1 & (token >> 60)) != 0;
}
/**
* Get the nesting depth of startObject calls from the token.
*/
public static int getDepthFromToken(long token) {
return (int) (0x01ff & (token >> 51));
}
/**
* Get the object ID from the token. The object ID is a serial number for the
* startObject calls that have happened on this object. The values are truncated
* to 9 bits, but that is sufficient for error checking.
*/
public static int getObjectIdFromToken(long token) {
return (int) (0x07ffff & (token >> 32));
}
/**
* Get the location of the offset recorded in the token.
*/
public static int getOffsetFromToken(long token) {
return (int) token;
}
/**
* Convert the object ID to the ordinal value -- the n-th call to startObject.
* The object IDs start at -1 and count backwards, so that the value is unlikely
* to alias with an actual size field that had been written.
*/
public static int convertObjectIdToOrdinal(int objectId) {
return (-1 & 0x07ffff) - objectId;
}
/**
* Return a debugging string of a token.
*/
public static String token2String(long token) {
if (token == 0L) {
return "Token(0)";
} else {
return "Token(val=0x" + Long.toHexString(token)
+ " depth=" + getDepthFromToken(token)
+ " object=" + convertObjectIdToOrdinal(getObjectIdFromToken(token))
+ " tagSize=" + getTagSizeFromToken(token)
+ " offset=" + getOffsetFromToken(token)
+ ')';
}
}
}