Ruby: include/ruby/io/buffer.h Source File

Ruby 3.3.7p123 (2025-01-15 revision be31f993d7fa0219d85f7b3c694d454da4ecc10b)

buffer.h
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1#ifndef RUBY_IO_BUFFER_H
2#define RUBY_IO_BUFFER_H
13
14#pragma once
15
16#include "ruby/ruby.h"
17#include "ruby/internal/config.h"
18
19 RBIMPL_SYMBOL_EXPORT_BEGIN()
20
21// WARNING: This entire interface is experimental and may change in the future!
22#define RB_IO_BUFFER_EXPERIMENTAL 1
23
24#define RUBY_IO_BUFFER_VERSION 2
25
26// The `IO::Buffer` class.
27 RUBY_EXTERN VALUE rb_cIOBuffer;
28
29// The operating system page size.
30 RUBY_EXTERN size_t RUBY_IO_BUFFER_PAGE_SIZE;
31
32// The default buffer size, usually a (small) multiple of the page size.
33// Can be overridden by the RUBY_IO_BUFFER_DEFAULT_SIZE environment variable.
34 RUBY_EXTERN size_t RUBY_IO_BUFFER_DEFAULT_SIZE;
35
36// Represents the internal state of the buffer.
37// More than one flag can be set at a time.
38enum rb_io_buffer_flags {
39 // The memory in the buffer is owned by someone else.
40 // More specifically, it means that someone else owns the buffer and we shouldn't try to resize it.
41 RB_IO_BUFFER_EXTERNAL = 1,
42 // The memory in the buffer is allocated internally.
43 RB_IO_BUFFER_INTERNAL = 2,
44 // The memory in the buffer is mapped.
45 // A non-private mapping is marked as external.
46 RB_IO_BUFFER_MAPPED = 4,
47
48 // A mapped buffer that is also shared.
49 RB_IO_BUFFER_SHARED = 8,
50
51 // The buffer is locked and cannot be resized.
52 // More specifically, it means we can't change the base address or size.
53 // A buffer is typically locked before a system call that uses the data.
54 RB_IO_BUFFER_LOCKED = 32,
55
56 // The buffer mapping is private and will not impact other processes or the underlying file.
57 RB_IO_BUFFER_PRIVATE = 64,
58
59 // The buffer is read-only and cannot be modified.
60 RB_IO_BUFFER_READONLY = 128,
61
62 // The buffer is backed by a file.
63 RB_IO_BUFFER_FILE = 256,
64};
65
66// Represents the endian of the data types.
67enum rb_io_buffer_endian {
68 // The least significant units are put first.
69 RB_IO_BUFFER_LITTLE_ENDIAN = 4,
70 RB_IO_BUFFER_BIG_ENDIAN = 8,
71
72#if defined(WORDS_BIGENDIAN)
73 RB_IO_BUFFER_HOST_ENDIAN = RB_IO_BUFFER_BIG_ENDIAN,
74#else
75 RB_IO_BUFFER_HOST_ENDIAN = RB_IO_BUFFER_LITTLE_ENDIAN,
76#endif
77
78 RB_IO_BUFFER_NETWORK_ENDIAN = RB_IO_BUFFER_BIG_ENDIAN
79};
80
81 VALUE rb_io_buffer_new(void *base, size_t size, enum rb_io_buffer_flags flags);
82 VALUE rb_io_buffer_map(VALUE io, size_t size, rb_off_t offset, enum rb_io_buffer_flags flags);
83
84 VALUE rb_io_buffer_lock(VALUE self);
85 VALUE rb_io_buffer_unlock(VALUE self);
86int rb_io_buffer_try_unlock(VALUE self);
87
88 VALUE rb_io_buffer_free(VALUE self);
89 VALUE rb_io_buffer_free_locked(VALUE self);
90
91// Access the internal buffer and flags. Validates the pointers.
92// The points may not remain valid if the source buffer is manipulated.
93// Consider using rb_io_buffer_lock if needed.
94enum rb_io_buffer_flags rb_io_buffer_get_bytes(VALUE self, void **base, size_t *size);
95void rb_io_buffer_get_bytes_for_reading(VALUE self, const void **base, size_t *size);
96void rb_io_buffer_get_bytes_for_writing(VALUE self, void **base, size_t *size);
97
98 VALUE rb_io_buffer_transfer(VALUE self);
99void rb_io_buffer_resize(VALUE self, size_t size);
100void rb_io_buffer_clear(VALUE self, uint8_t value, size_t offset, size_t length);
101
102// The length is the minimum required length.
103 VALUE rb_io_buffer_read(VALUE self, VALUE io, size_t length, size_t offset);
104 VALUE rb_io_buffer_pread(VALUE self, VALUE io, rb_off_t from, size_t length, size_t offset);
105 VALUE rb_io_buffer_write(VALUE self, VALUE io, size_t length, size_t offset);
106 VALUE rb_io_buffer_pwrite(VALUE self, VALUE io, rb_off_t from, size_t length, size_t offset);
107
108 RBIMPL_SYMBOL_EXPORT_END()
109
110#endif /* RUBY_IO_BUFFER_H */
RUBY_EXTERN
#define RUBY_EXTERN
Declaration of externally visible global variables.
Definition dllexport.h:45
RBIMPL_SYMBOL_EXPORT_END
#define RBIMPL_SYMBOL_EXPORT_END()
Counterpart of RBIMPL_SYMBOL_EXPORT_BEGIN.
Definition dllexport.h:74
RBIMPL_SYMBOL_EXPORT_BEGIN
#define RBIMPL_SYMBOL_EXPORT_BEGIN()
Shortcut macro equivalent to RUBY_SYMBOL_EXPORT_BEGIN extern "C" {.
Definition dllexport.h:65
ruby.h
VALUE
uintptr_t VALUE
Type that represents a Ruby object.
Definition value.h:40