/*
* Copyright (C) 2014 Square, Inc.
*
* 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 okio;
import java.io.IOException;
import java.io.InputStream;
import java.nio.charset.Charset;
/**
* A source that keeps a buffer internally so that callers can do small reads
* without a performance penalty. It also allows clients to read ahead,
* buffering as much as necessary before consuming input.
*/
public interface BufferedSource extends Source {
/** Returns this source's internal buffer. */
Buffer buffer();
/**
* Returns true if there are no more bytes in this source. This will block
* until there are bytes to read or the source is definitely exhausted.
*/
boolean exhausted() throws IOException;
/**
* Returns when the buffer contains at least {@code byteCount} bytes. Throws
* an {@link java.io.EOFException} if the source is exhausted before the
* required bytes can be read.
*/
void require(long byteCount) throws IOException;
/**
* Returns true when the buffer contains at least {@code byteCount} bytes,
* expanding it as necessary. Returns false if the source is exhausted before
* the requested bytes can be read.
*/
boolean request(long byteCount) throws IOException;
/** Removes a byte from this source and returns it. */
byte readByte() throws IOException;
/** Removes two bytes from this source and returns a big-endian short. */
short readShort() throws IOException;
/** Removes two bytes from this source and returns a little-endian short. */
short readShortLe() throws IOException;
/** Removes four bytes from this source and returns a big-endian int. */
int readInt() throws IOException;
/** Removes four bytes from this source and returns a little-endian int. */
int readIntLe() throws IOException;
/** Removes eight bytes from this source and returns a big-endian long. */
long readLong() throws IOException;
/** Removes eight bytes from this source and returns a little-endian long. */
long readLongLe() throws IOException;
/**
* Reads a long from this source in signed decimal form (i.e., as a string in base 10 with
* optional leading '-'). This will iterate until a non-digit character is found.
*
* @throws NumberFormatException if the found digits do not fit into a {@code long} or a decimal
* number was not present.
*/
long readDecimalLong() throws IOException;
/**
* Reads a long form this source in hexadecimal form (i.e., as a string in base 16). This will
* iterate until a non-hexadecimal character is found.
*
* @throws NumberFormatException if the found hexadecimal does not fit into a {@code long} or
* hexadecimal was not found.
*/
long readHexadecimalUnsignedLong() throws IOException;
/**
* Reads and discards {@code byteCount} bytes from this source. Throws an
* {@link java.io.EOFException} if the source is exhausted before the
* requested bytes can be skipped.
*/
void skip(long byteCount) throws IOException;
/** Removes all bytes bytes from this and returns them as a byte string. */
ByteString readByteString() throws IOException;
/** Removes {@code byteCount} bytes from this and returns them as a byte string. */
ByteString readByteString(long byteCount) throws IOException;
/** Removes all bytes from this and returns them as a byte array. */
byte[] readByteArray() throws IOException;
/** Removes {@code byteCount} bytes from this and returns them as a byte array. */
byte[] readByteArray(long byteCount) throws IOException;
/**
* Removes up to {@code sink.length} bytes from this and copies them into {@code sink}.
* Returns the number of bytes read, or -1 if this source is exhausted.
*/
int read(byte[] sink) throws IOException;
/**
* Removes exactly {@code sink.length} bytes from this and copies them into {@code sink}.
* Throws an {@link java.io.EOFException} if the requested number of bytes cannot be read.
*/
void readFully(byte[] sink) throws IOException;
/**
* Removes up to {@code byteCount} bytes from this and copies them into {@code sink} at
* {@code offset}. Returns the number of bytes read, or -1 if this source is exhausted.
*/
int read(byte[] sink, int offset, int byteCount) throws IOException;
/**
* Removes exactly {@code byteCount} bytes from this and appends them to
* {@code sink}. Throws an {@link java.io.EOFException} if the requested
* number of bytes cannot be read.
*/
void readFully(Buffer sink, long byteCount) throws IOException;
/**
* Removes all bytes from this and appends them to {@code sink}. Returns the
* total number of bytes written to {@code sink} which will be 0 if this is
* exhausted.
*/
long readAll(Sink sink) throws IOException;
/** Removes all bytes from this, decodes them as UTF-8, and returns the string. */
String readUtf8() throws IOException;
/**
* Removes {@code byteCount} bytes from this, decodes them as UTF-8, and
* returns the string.
*/
String readUtf8(long byteCount) throws IOException;
/**
* Removes and returns characters up to but not including the next line break.
* A line break is either {@code "\n"} or {@code "\r\n"}; these characters are
* not included in the result.
*
* <p><strong>On the end of the stream this method returns null,</strong> just
* like {@link java.io.BufferedReader}. If the source doesn't end with a line
* break then an implicit line break is assumed. Null is returned once the
* source is exhausted. Use this for human-generated data, where a trailing
* line break is optional.
*/
String readUtf8Line() throws IOException;
/**
* Removes and returns characters up to but not including the next line break.
* A line break is either {@code "\n"} or {@code "\r\n"}; these characters are
* not included in the result.
*
* <p><strong>On the end of the stream this method throws.</strong> Every call
* must consume either '\r\n' or '\n'. If these characters are absent in the
* stream, an {@link java.io.EOFException} is thrown. Use this for
* machine-generated data where a missing line break implies truncated input.
*/
String readUtf8LineStrict() throws IOException;
/**
* Removes and returns a single UTF-8 code point, reading between 1 and 4 bytes as necessary.
*
* <p>If this source is exhausted before a complete code point can be read, this throws an {@link
* java.io.EOFException} and consumes no input.
*
* <p>If this source doesn't start with a properly-encoded UTF-8 code point, this method will
* remove 1 or more non-UTF-8 bytes and return the replacement character ({@code U+FFFD}). This
* covers encoding problems (the input is not properly-encoded UTF-8), characters out of range
* (beyond the 0x10ffff limit of Unicode), code points for UTF-16 surrogates (U+d800..U+dfff) and
* overlong encodings (such as {@code 0xc080} for the NUL character in modified UTF-8).
*/
int readUtf8CodePoint() throws IOException;
/**
* Removes all bytes from this, decodes them as {@code charset}, and returns
* the string.
*/
String readString(Charset charset) throws IOException;
/**
* Removes {@code byteCount} bytes from this, decodes them as {@code charset},
* and returns the string.
*/
String readString(long byteCount, Charset charset) throws IOException;
/**
* Returns the index of the first {@code b} in the buffer. This expands the
* buffer as necessary until {@code b} is found. This reads an unbounded
* number of bytes into the buffer. Returns -1 if the stream is exhausted
* before the requested byte is found.
*/
long indexOf(byte b) throws IOException;
/**
* Returns the index of the first {@code b} in the buffer at or after {@code
* fromIndex}. This expands the buffer as necessary until {@code b} is found.
* This reads an unbounded number of bytes into the buffer. Returns -1 if the
* stream is exhausted before the requested byte is found.
*/
long indexOf(byte b, long fromIndex) throws IOException;
/**
* Returns the index of the first match for {@code bytes} in the buffer. This expands the buffer
* as necessary until {@code bytes} is found. This reads an unbounded number of bytes into the
* buffer. Returns -1 if the stream is exhausted before the requested bytes are found.
*/
long indexOf(ByteString bytes) throws IOException;
/**
* Returns the index of the first match for {@code bytes} in the buffer at or after {@code
* fromIndex}. This expands the buffer as necessary until {@code bytes} is found. This reads an
* unbounded number of bytes into the buffer. Returns -1 if the stream is exhausted before the
* requested bytes are found.
*/
long indexOf(ByteString bytes, long fromIndex) throws IOException;
/**
* Returns the index of the first byte in {@code targetBytes} in the buffer.
* This expands the buffer as necessary until a target byte is found. This
* reads an unbounded number of bytes into the buffer. Returns -1 if the
* stream is exhausted before the requested byte is found.
*/
long indexOfElement(ByteString targetBytes) throws IOException;
/**
* Returns the index of the first byte in {@code targetBytes} in the buffer
* at or after {@code fromIndex}. This expands the buffer as necessary until
* a target byte is found. This reads an unbounded number of bytes into the
* buffer. Returns -1 if the stream is exhausted before the requested byte is
* found.
*/
long indexOfElement(ByteString targetBytes, long fromIndex) throws IOException;
/** Returns an input stream that reads from this source. */
InputStream inputStream();
}