nl.topicus.jdbc.shaded.io.grpc.Status Maven / Gradle / Ivy
/*
* Copyright 2014, gRPC Authors All rights reserved.
*
* 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 nl.topicus.jdbc.shaded.io.grpc;
import static nl.topicus.jdbc.shaded.com.google.common.base.Charsets.US_ASCII;
import static nl.topicus.jdbc.shaded.com.google.common.base.Charsets.UTF_8;
import static nl.topicus.jdbc.shaded.com.google.common.base.Preconditions.checkNotNull;
import static nl.topicus.jdbc.shaded.com.google.common.base.Throwables.getStackTraceAsString;
import nl.topicus.jdbc.shaded.com.google.common.base.MoreObjects;
import nl.topicus.jdbc.shaded.com.google.common.base.Objects;
import nl.topicus.jdbc.shaded.io.grpc.Metadata.TrustedAsciiMarshaller;
import java.nio.ByteBuffer;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.TreeMap;
import nl.topicus.jdbc.shaded.javax.annotation.Nullable;
import nl.topicus.jdbc.shaded.javax.annotation.concurrent.Immutable;
/**
* Defines the status of an operation by providing a standard {@link Code} in conjunction with an
* optional descriptive message. Instances of {@code Status} are created by starting with the
* template for the appropriate {@link Status.Code} and supplementing it with additional
* information: {@code Status.NOT_FOUND.withDescription("Could not find 'important_file.txt'");}
*
* For clients, every remote call will return a status on completion. In the case of errors this
* status may be propagated to blocking stubs as a {@link RuntimeException} or to a listener as an
* explicit parameter.
*
*
Similarly servers can report a status by throwing {@link StatusRuntimeException}
* or by passing the status to a callback.
*
*
Utility functions are provided to convert a status to an exception and to extract them
* back out.
*/
@Immutable
public final class Status {
/**
* The set of canonical status codes. If new codes are added over time they must choose
* a numerical value that does not collide with any previously used value.
*/
public enum Code {
/**
* The operation completed successfully.
*/
OK(0),
/**
* The operation was cancelled (typically by the caller).
*/
CANCELLED(1),
/**
* Unknown error. An example of where this error may be returned is
* if a Status value received from another address space belongs to
* an error-space that is not known in this address space. Also
* errors raised by APIs that do not return enough error information
* may be converted to this error.
*/
UNKNOWN(2),
/**
* Client specified an invalid argument. Note that this differs
* from FAILED_PRECONDITION. INVALID_ARGUMENT indicates arguments
* that are problematic regardless of the state of the system
* (e.g., a malformed file name).
*/
INVALID_ARGUMENT(3),
/**
* Deadline expired before operation could complete. For operations
* that change the state of the system, this error may be returned
* even if the operation has completed successfully. For example, a
* successful response from a server could have been delayed long
* enough for the deadline to expire.
*/
DEADLINE_EXCEEDED(4),
/**
* Some requested entity (e.g., file or directory) was not found.
*/
NOT_FOUND(5),
/**
* Some entity that we attempted to create (e.g., file or directory) already exists.
*/
ALREADY_EXISTS(6),
/**
* The caller does not have permission to execute the specified
* operation. PERMISSION_DENIED must not be used for rejections
* caused by exhausting some resource (use RESOURCE_EXHAUSTED
* instead for those errors). PERMISSION_DENIED must not be
* used if the caller cannot be identified (use UNAUTHENTICATED
* instead for those errors).
*/
PERMISSION_DENIED(7),
/**
* Some resource has been exhausted, perhaps a per-user quota, or
* perhaps the entire file system is out of space.
*/
RESOURCE_EXHAUSTED(8),
/**
* Operation was rejected because the system is not in a state
* required for the operation's execution. For example, directory
* to be deleted may be non-empty, an rmdir operation is applied to
* a non-directory, etc.
*
*
A litmus test that may help a service implementor in deciding
* between FAILED_PRECONDITION, ABORTED, and UNAVAILABLE:
* (a) Use UNAVAILABLE if the client can retry just the failing call.
* (b) Use ABORTED if the client should retry at a higher-level
* (e.g., restarting a read-modify-write sequence).
* (c) Use FAILED_PRECONDITION if the client should not retry until
* the system state has been explicitly fixed. E.g., if an "rmdir"
* fails because the directory is non-empty, FAILED_PRECONDITION
* should be returned since the client should not retry unless
* they have first fixed up the directory by deleting files from it.
*/
FAILED_PRECONDITION(9),
/**
* The operation was aborted, typically due to a concurrency issue
* like sequencer check failures, transaction aborts, etc.
*
*
See litmus test above for deciding between FAILED_PRECONDITION,
* ABORTED, and UNAVAILABLE.
*/
ABORTED(10),
/**
* Operation was attempted past the valid range. E.g., seeking or
* reading past end of file.
*
*
Unlike INVALID_ARGUMENT, this error indicates a problem that may
* be fixed if the system state changes. For example, a 32-bit file
* system will generate INVALID_ARGUMENT if asked to read at an
* offset that is not in the range [0,2^32-1], but it will generate
* OUT_OF_RANGE if asked to read from an offset past the current
* file size.
*
*
There is a fair bit of overlap between FAILED_PRECONDITION and OUT_OF_RANGE.
* We recommend using OUT_OF_RANGE (the more specific error) when it applies
* so that callers who are iterating through
* a space can easily look for an OUT_OF_RANGE error to detect when they are done.
*/
OUT_OF_RANGE(11),
/**
* Operation is not implemented or not supported/enabled in this service.
*/
UNIMPLEMENTED(12),
/**
* Internal errors. Means some invariants expected by underlying
* system has been broken. If you see one of these errors,
* something is very broken.
*/
INTERNAL(13),
/**
* The service is currently unavailable. This is a most likely a
* transient condition and may be corrected by retrying with
* a backoff.
*
*
See litmus test above for deciding between FAILED_PRECONDITION,
* ABORTED, and UNAVAILABLE.
*/
UNAVAILABLE(14),
/**
* Unrecoverable data loss or corruption.
*/
DATA_LOSS(15),
/**
* The request does not have valid authentication credentials for the
* operation.
*/
UNAUTHENTICATED(16);
private final int value;
@SuppressWarnings("ImmutableEnumChecker") // we make sure the byte[] can't be modified
private final byte[] valueAscii;
private Code(int value) {
this.value = value;
this.valueAscii = Integer.toString(value).getBytes(US_ASCII);
}
/**
* The numerical value of the code.
*/
public int value() {
return value;
}
/**
* Returns a {@link Status} object corresponding to this status code.
*/
public Status toStatus() {
return STATUS_LIST.get(value);
}
private byte[] valueAscii() {
return valueAscii;
}
}
// Create the canonical list of Status instances indexed by their code values.
private static final List STATUS_LIST = buildStatusList();
private static List buildStatusList() {
TreeMap canonicalizer = new TreeMap();
for (Code code : Code.values()) {
Status replaced = canonicalizer.put(code.value(), new Status(code));
if (replaced != null) {
throw new IllegalStateException("Code value duplication between "
+ replaced.getCode().name() + " & " + code.name());
}
}
return Collections.unmodifiableList(new ArrayList(canonicalizer.values()));
}
// A pseudo-enum of Status instances mapped 1:1 with values in Code. This simplifies construction
// patterns for derived instances of Status.
/** The operation completed successfully. */
public static final Status OK = Code.OK.toStatus();
/** The operation was cancelled (typically by the caller). */
public static final Status CANCELLED = Code.CANCELLED.toStatus();
/** Unknown error. See {@link Code#UNKNOWN}. */
public static final Status UNKNOWN = Code.UNKNOWN.toStatus();
/** Client specified an invalid argument. See {@link Code#INVALID_ARGUMENT}. */
public static final Status INVALID_ARGUMENT = Code.INVALID_ARGUMENT.toStatus();
/** Deadline expired before operation could complete. See {@link Code#DEADLINE_EXCEEDED}. */
public static final Status DEADLINE_EXCEEDED = Code.DEADLINE_EXCEEDED.toStatus();
/** Some requested entity (e.g., file or directory) was not found. */
public static final Status NOT_FOUND = Code.NOT_FOUND.toStatus();
/** Some entity that we attempted to create (e.g., file or directory) already exists. */
public static final Status ALREADY_EXISTS = Code.ALREADY_EXISTS.toStatus();
/**
* The caller does not have permission to execute the specified operation. See {@link
* Code#PERMISSION_DENIED}.
*/
public static final Status PERMISSION_DENIED = Code.PERMISSION_DENIED.toStatus();
/** The request does not have valid authentication credentials for the operation. */
public static final Status UNAUTHENTICATED = Code.UNAUTHENTICATED.toStatus();
/**
* Some resource has been exhausted, perhaps a per-user quota, or perhaps the entire file system
* is out of space.
*/
public static final Status RESOURCE_EXHAUSTED = Code.RESOURCE_EXHAUSTED.toStatus();
/**
* Operation was rejected because the system is not in a state required for the operation's
* execution. See {@link Code#FAILED_PRECONDITION}.
*/
public static final Status FAILED_PRECONDITION =
Code.FAILED_PRECONDITION.toStatus();
/**
* The operation was aborted, typically due to a concurrency issue like sequencer check failures,
* transaction aborts, etc. See {@link Code#ABORTED}.
*/
public static final Status ABORTED = Code.ABORTED.toStatus();
/** Operation was attempted past the valid range. See {@link Code#OUT_OF_RANGE}. */
public static final Status OUT_OF_RANGE = Code.OUT_OF_RANGE.toStatus();
/** Operation is not implemented or not supported/enabled in this service. */
public static final Status UNIMPLEMENTED = Code.UNIMPLEMENTED.toStatus();
/** Internal errors. See {@link Code#INTERNAL}. */
public static final Status INTERNAL = Code.INTERNAL.toStatus();
/** The service is currently unavailable. See {@link Code#UNAVAILABLE}. */
public static final Status UNAVAILABLE = Code.UNAVAILABLE.toStatus();
/** Unrecoverable data loss or corruption. */
public static final Status DATA_LOSS = Code.DATA_LOSS.toStatus();
/**
* Return a {@link Status} given a canonical error {@link Code} value.
*/
public static Status fromCodeValue(int codeValue) {
if (codeValue < 0 || codeValue > STATUS_LIST.size()) {
return UNKNOWN.withDescription("Unknown code " + codeValue);
} else {
return STATUS_LIST.get(codeValue);
}
}
private static Status fromCodeValue(byte[] asciiCodeValue) {
if (asciiCodeValue.length == 1 && asciiCodeValue[0] == '0') {
return Status.OK;
}
return fromCodeValueSlow(asciiCodeValue);
}
@SuppressWarnings("fallthrough")
private static Status fromCodeValueSlow(byte[] asciiCodeValue) {
int index = 0;
int codeValue = 0;
switch (asciiCodeValue.length) {
case 2:
if (asciiCodeValue[index] < '0' || asciiCodeValue[index] > '9') {
break;
}
codeValue += (asciiCodeValue[index++] - '0') * 10;
// fall through
case 1:
if (asciiCodeValue[index] < '0' || asciiCodeValue[index] > '9') {
break;
}
codeValue += asciiCodeValue[index] - '0';
if (codeValue < STATUS_LIST.size()) {
return STATUS_LIST.get(codeValue);
}
break;
default:
break;
}
return UNKNOWN.withDescription("Unknown code " + new String(asciiCodeValue, US_ASCII));
}
/**
* Return a {@link Status} given a canonical error {@link Code} object.
*/
public static Status fromCode(Code code) {
return code.toStatus();
}
/**
* Key to bind status code to trailing metadata.
*/
static final Metadata.Key CODE_KEY
= Metadata.Key.of("grpc-status", false /* not pseudo */, new StatusCodeMarshaller());
/**
* Marshals status messages for ({@link #MESSAGE_KEY}. gRPC does not use binary coding of
* status messages by default, which makes sending arbitrary strings difficult. This marshaller
* uses ASCII printable characters by default, and percent encodes (e.g. %0A) all non ASCII bytes.
* This leads to normal text being mostly readable (especially useful for debugging), and special
* text still being sent.
*
* By default, the HTTP spec says that header values must be encoded using a strict subset of
* ASCII (See RFC 7230 section 3.2.6). HTTP/2 HPACK allows use of arbitrary binary headers, but
* we do not use them for interoperating with existing HTTP/1.1 code. Since the grpc-message
* is encoded to such a header, it needs to not use forbidden characters.
*
*
This marshaller works by converting the passed in string into UTF-8, checking to see if
* each individual byte is an allowable byte, and then either percent encoding or passing it
* through. When percent encoding, the byte is converted into hexadecimal notation with a '%'
* prepended.
*
*
When unmarshalling, bytes are passed through unless they match the "%XX" pattern. If they
* do match, the unmarshaller attempts to convert them back into their original UTF-8 byte
* sequence. After the input header bytes are converted into UTF-8 bytes, the new byte array is
* reinterpretted back as a string.
*/
private static final TrustedAsciiMarshaller STATUS_MESSAGE_MARSHALLER =
new StatusMessageMarshaller();
/**
* Key to bind status message to trailing metadata.
*/
static final Metadata.Key MESSAGE_KEY =
Metadata.Key.of("grpc-message", false /* not pseudo */, STATUS_MESSAGE_MARSHALLER);
/**
* Extract an error {@link Status} from the causal chain of a {@link Throwable}.
* If no status can be found, a status is created with {@link Code#UNKNOWN} as its code and
* {@code t} as its cause.
*
* @return non-{@code null} status
*/
public static Status fromThrowable(Throwable t) {
Throwable cause = checkNotNull(t, "t");
while (cause != null) {
if (cause instanceof StatusException) {
return ((StatusException) cause).getStatus();
} else if (cause instanceof StatusRuntimeException) {
return ((StatusRuntimeException) cause).getStatus();
}
cause = cause.getCause();
}
// Couldn't find a cause with a Status
return UNKNOWN.withCause(t);
}
/**
* Extract an error trailers from the causal chain of a {@link Throwable}.
*
* @return the trailers or {@code null} if not found.
*/
@ExperimentalApi
public static Metadata trailersFromThrowable(Throwable t) {
Throwable cause = checkNotNull(t, "t");
while (cause != null) {
if (cause instanceof StatusException) {
return ((StatusException) cause).getTrailers();
} else if (cause instanceof StatusRuntimeException) {
return ((StatusRuntimeException) cause).getTrailers();
}
cause = cause.getCause();
}
return null;
}
static String formatThrowableMessage(Status status) {
if (status.description == null) {
return status.code.toString();
} else {
return status.code + ": " + status.description;
}
}
private final Code code;
private final String description;
private final Throwable cause;
private Status(Code code) {
this(code, null, null);
}
private Status(Code code, @Nullable String description, @Nullable Throwable cause) {
this.code = checkNotNull(code, "code");
this.description = description;
this.cause = cause;
}
/**
* Create a derived instance of {@link Status} with the given cause.
* However, the cause is not transmitted from server to client.
*/
public Status withCause(Throwable cause) {
if (Objects.equal(this.cause, cause)) {
return this;
}
return new Status(this.code, this.description, cause);
}
/**
* Create a derived instance of {@link Status} with the given description. Leading and trailing
* whitespace may be removed; this may change in the future.
*/
public Status withDescription(String description) {
if (Objects.equal(this.description, description)) {
return this;
}
return new Status(this.code, description, this.cause);
}
/**
* Create a derived instance of {@link Status} augmenting the current description with
* additional detail. Leading and trailing whitespace may be removed; this may change in the
* future.
*/
public Status augmentDescription(String additionalDetail) {
if (additionalDetail == null) {
return this;
} else if (this.description == null) {
return new Status(this.code, additionalDetail, this.cause);
} else {
return new Status(this.code, this.description + "\n" + additionalDetail, this.cause);
}
}
/**
* The canonical status code.
*/
public Code getCode() {
return code;
}
/**
* A description of this status for human consumption.
*/
@Nullable
public String getDescription() {
return description;
}
/**
* The underlying cause of an error.
* Note that the cause is not transmitted from server to client.
*/
@Nullable
public Throwable getCause() {
return cause;
}
/**
* Is this status OK, i.e., not an error.
*/
public boolean isOk() {
return Code.OK == code;
}
/**
* Convert this {@link Status} to a {@link RuntimeException}. Use {@link #fromThrowable}
* to recover this {@link Status} instance when the returned exception is in the causal chain.
*/
public StatusRuntimeException asRuntimeException() {
return new StatusRuntimeException(this);
}
/**
* Same as {@link #asRuntimeException()} but includes the provided trailers in the returned
* exception.
*/
@ExperimentalApi
public StatusRuntimeException asRuntimeException(Metadata trailers) {
return new StatusRuntimeException(this, trailers);
}
/**
* Convert this {@link Status} to an {@link Exception}. Use {@link #fromThrowable}
* to recover this {@link Status} instance when the returned exception is in the causal chain.
*/
public StatusException asException() {
return new StatusException(this);
}
/**
* Same as {@link #asException()} but includes the provided trailers in the returned exception.
*/
@ExperimentalApi
public StatusException asException(Metadata trailers) {
return new StatusException(this, trailers);
}
/** A string representation of the status useful for debugging. */
@Override
public String toString() {
return MoreObjects.toStringHelper(this)
.add("code", code.name())
.add("description", description)
.add("cause", cause != null ? getStackTraceAsString(cause) : cause)
.toString();
}
private static final class StatusCodeMarshaller implements TrustedAsciiMarshaller {
@Override
public byte[] toAsciiString(Status status) {
return status.getCode().valueAscii();
}
@Override
public Status parseAsciiString(byte[] serialized) {
return fromCodeValue(serialized);
}
}
private static final class StatusMessageMarshaller implements TrustedAsciiMarshaller {
private static final byte[] HEX =
{'0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'A', 'B', 'C', 'D', 'E', 'F'};
@Override
public byte[] toAsciiString(String value) {
byte[] valueBytes = value.getBytes(UTF_8);
for (int i = 0; i < valueBytes.length; i++) {
byte b = valueBytes[i];
// If there are only non escaping characters, skip the slow path.
if (isEscapingChar(b)) {
return toAsciiStringSlow(valueBytes, i);
}
}
return valueBytes;
}
private static boolean isEscapingChar(byte b) {
return b < ' ' || b >= '~' || b == '%';
}
/**
* @param valueBytes the UTF-8 bytes
* @param ri The reader index, pointed at the first byte that needs escaping.
*/
private static byte[] toAsciiStringSlow(byte[] valueBytes, int ri) {
byte[] escapedBytes = new byte[ri + (valueBytes.length - ri) * 3];
// copy over the good bytes
if (ri != 0) {
System.arraycopy(valueBytes, 0, escapedBytes, 0, ri);
}
int wi = ri;
for (; ri < valueBytes.length; ri++) {
byte b = valueBytes[ri];
// Manually implement URL encoding, per the gRPC spec.
if (isEscapingChar(b)) {
escapedBytes[wi] = '%';
escapedBytes[wi + 1] = HEX[(b >> 4) & 0xF];
escapedBytes[wi + 2] = HEX[b & 0xF];
wi += 3;
continue;
}
escapedBytes[wi++] = b;
}
byte[] dest = new byte[wi];
System.arraycopy(escapedBytes, 0, dest, 0, wi);
return dest;
}
@SuppressWarnings("deprecation") // Use fast but deprecated String ctor
@Override
public String parseAsciiString(byte[] value) {
for (int i = 0; i < value.length; i++) {
byte b = value[i];
if (b < ' ' || b >= '~' || (b == '%' && i + 2 < value.length)) {
return parseAsciiStringSlow(value);
}
}
return new String(value, 0);
}
private static String parseAsciiStringSlow(byte[] value) {
ByteBuffer buf = ByteBuffer.allocate(value.length);
for (int i = 0; i < value.length;) {
if (value[i] == '%' && i + 2 < value.length) {
try {
buf.put((byte)Integer.parseInt(new String(value, i + 1, 2, US_ASCII), 16));
i += 3;
continue;
} catch (NumberFormatException e) {
// ignore, fall through, just push the bytes.
}
}
buf.put(value[i]);
i += 1;
}
return new String(buf.array(), 0, buf.position(), UTF_8);
}
}
/**
* Equality on Statuses is not well defined. Instead, do comparison based on their Code with
* {@link #getCode}. The description and cause of the Status are unlikely to be stable, and
* additional fields may be added to Status in the future.
*/
@Override
public boolean equals(Object obj) {
return super.equals(obj);
}
/**
* Hash codes on Statuses are not well defined.
*
* @see #equals
*/
@Override
public int hashCode() {
return super.hashCode();
}
}