1// Protocol Buffers - Google's data interchange format
2// Copyright 2008 Google Inc.  All rights reserved.
3// https://developers.google.com/protocol-buffers/
4//
5// Redistribution and use in source and binary forms, with or without
6// modification, are permitted provided that the following conditions are
7// met:
8//
9//     * Redistributions of source code must retain the above copyright
10// notice, this list of conditions and the following disclaimer.
11//     * Redistributions in binary form must reproduce the above
12// copyright notice, this list of conditions and the following disclaimer
13// in the documentation and/or other materials provided with the
14// distribution.
15//     * Neither the name of Google Inc. nor the names of its
16// contributors may be used to endorse or promote products derived from
17// this software without specific prior written permission.
18//
19// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
20// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
21// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
22// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
23// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
24// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
25// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
26// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
27// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
28// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
29// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
30
31#import <Foundation/Foundation.h>
32
33@class GPBMessage;
34@class GPBExtensionRegistry;
35
36NS_ASSUME_NONNULL_BEGIN
37
38/// Reads and decodes protocol message fields.
39///
40/// The common uses of protocol buffers shouldn't need to use this class.
41/// @c GPBMessage's provide a @c +parseFromData:error: and @c
42/// +parseFromData:extensionRegistry:error: method that will decode a
43/// message for you.
44///
45/// @note Subclassing of GPBCodedInputStream is NOT supported.
46@interface GPBCodedInputStream : NSObject
47
48/// Creates a new stream wrapping some data.
49+ (instancetype)streamWithData:(NSData *)data;
50
51/// Initializes a stream wrapping some data.
52- (instancetype)initWithData:(NSData *)data;
53
54/// Attempt to read a field tag, returning zero if we have reached EOF.
55/// Protocol message parsers use this to read tags, since a protocol message
56/// may legally end wherever a tag occurs, and zero is not a valid tag number.
57- (int32_t)readTag;
58
59/// Read and return a double.
60- (double)readDouble;
61/// Read and return a float.
62- (float)readFloat;
63/// Read and return a uint64.
64- (uint64_t)readUInt64;
65/// Read and return a uint32.
66- (uint32_t)readUInt32;
67/// Read and return an int64.
68- (int64_t)readInt64;
69/// Read and return an int32.
70- (int32_t)readInt32;
71/// Read and return a fixed64.
72- (uint64_t)readFixed64;
73/// Read and return a fixed32.
74- (uint32_t)readFixed32;
75/// Read and return an enum (int).
76- (int32_t)readEnum;
77/// Read and return a sfixed32.
78- (int32_t)readSFixed32;
79/// Read and return a sfixed64.
80- (int64_t)readSFixed64;
81/// Read and return a sint32.
82- (int32_t)readSInt32;
83/// Read and return a sint64.
84- (int64_t)readSInt64;
85/// Read and return a boolean.
86- (BOOL)readBool;
87/// Read and return a string.
88- (NSString *)readString;
89/// Read and return length delimited data.
90- (NSData *)readBytes;
91
92/// Read an embedded message field value from the stream.
93///
94/// @param message           The message to set fields on as they are read.
95/// @param extensionRegistry An optional extension registry to use to lookup
96///                          extensions for @message.
97- (void)readMessage:(GPBMessage *)message
98  extensionRegistry:(nullable GPBExtensionRegistry *)extensionRegistry;
99
100/// Reads and discards a single field, given its tag value.
101///
102/// @param tag The tag number of the field to skip.
103///
104/// @return NO if the tag is an endgroup tag (in which case nothing is skipped),
105///         YES in all other cases.
106- (BOOL)skipField:(int32_t)tag;
107
108/// Reads and discards an entire message.  This will read either until EOF
109/// or until an endgroup tag, whichever comes first.
110- (void)skipMessage;
111
112/// Check to see if the logical end of the stream has been reached.
113///
114/// This can return NO when there is no more data, but the current parsing
115/// expected more data.
116- (BOOL)isAtEnd;
117
118/// The offset into the stream.
119- (size_t)position;
120
121/// Verifies that the last call to @c -readTag returned the given tag value.
122/// This is used to verify that a nested group ended with the correct end tag.
123/// Throws @c NSParseErrorException if value does not match the last tag.
124///
125/// @param expected The tag that was expected.
126- (void)checkLastTagWas:(int32_t)expected;
127
128@end
129
130NS_ASSUME_NONNULL_END
131