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Filename : cdesc-Buffer.ri
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U:RDoc::NormalClass[iI"Buffer:ETI"IO::Buffer;TI"Object;To:RDoc::Markup::Document:@parts[o;;[o:RDoc::Markup::Paragraph;[I"LIO::Buffer is a efficient zero-copy buffer for input/output. There are ;TI"typical use cases:;To:RDoc::Markup::BlankLine�o:RDoc::Markup::List:
@type:BULLET:@items[	o:RDoc::Markup::ListItem:@label0;[o;	;[I"KCreate an empty buffer with ::new, fill it with buffer using #copy or ;TI"O#set_value, #set_string, get buffer with #get_string or write it directly ;TI"to some file with #write.;To;;0;[o;	;[I"MCreate a buffer mapped to some string with ::for, then it could be used ;TI"Pboth for reading with #get_string or #get_value, and writing (writing will ;TI"$change the source string, too).;To;;0;[o;	;[I"OCreate a buffer mapped to some file with ::map, then it could be used for ;TI"-reading and writing the underlying file.;To;;0;[o;	;[I"KCreate a string of a fixed size with ::string, then #read into it, or ;TI" modify it using #set_value.;T@o;	;[I"QInteraction with string and file memory is performed by efficient low-level ;TI" C mechanisms like `memcpy`.;T@o;	;[I"UThe class is meant to be an utility for implementing more high-level mechanisms ;TI"Tlike Fiber::Scheduler#io_read and Fiber::Scheduler#io_write and parsing binary ;TI"protocols.;T@S:RDoc::Markup::Heading:
leveli:	textI"Examples of Usage;T@o;	;[I"Empty buffer:;T@o:RDoc::Markup::Verbatim;[I">buffer = IO::Buffer.new(8)  # create empty 8-byte buffer
;TI"
# =>
;TI"3# #<IO::Buffer 0x0000555f5d1a5c50+8 INTERNAL>
;TI"# ...
;TI"buffer
;TI"
# =>
;TI"2# <IO::Buffer 0x0000555f5d156ab0+8 INTERNAL>
;TI"+# 0x00000000  00 00 00 00 00 00 00 00
;TI"abuffer.set_string('test', 2) # put there bytes of the "test" string, starting from offset 2
;TI"# => 4
;TI")buffer.get_string  # get the result
;TI"!# => "\x00\x00test\x00\x00"
;T:@format0o;	;[I"\Buffer from string:;T@o;;[I"string = 'data'
;TI"(IO::Buffer.for(string) do |buffer|
;TI"  buffer
;TI"  # =>
;TI"2  # #<IO::Buffer 0x00007f3f02be9b18+4 SLICE>
;TI"J  # 0x00000000  64 61 74 61                                     data
;TI"
;TI"C  buffer.get_string(2)  # read content starting from offset 2
;TI"  # => "ta"
;TI"K  buffer.set_string('---', 1) # write content, starting from offset 1
;TI"  # => 3
;TI"  buffer
;TI"  # =>
;TI"2  # #<IO::Buffer 0x00007f3f02be9b18+4 SLICE>
;TI"J  # 0x00000000  64 2d 2d 2d                                     d---
;TI".  string  # original string changed, too
;TI"  # => "d---"
;TI"	end
;T;0o;	;[I"\Buffer from file:;T@o;;[I")File.write('test.txt', 'test data')
;TI"# => 9
;TI"4buffer = IO::Buffer.map(File.open('test.txt'))
;TI"
# =>
;TI";# #<IO::Buffer 0x00007f3f0768c000+9 MAPPED IMMUTABLE>
;TI"# ...
;TI"Dbuffer.get_string(5, 2) # read 2 bytes, starting from offset 5
;TI"# => "da"
;TI"4buffer.set_string('---', 1) # attempt to write
;TI"J# in `set_string': Buffer is not writable! (IO::Buffer::AccessError)
;TI"
;TI"-# To create writable file-mapped buffer
;TI"@# Open file for read-write, pass size, offset, and flags=0
;TI"Cbuffer = IO::Buffer.map(File.open('test.txt', 'r+'), 9, 0, 0)
;TI"!buffer.set_string('---', 1)
;TI"# => 3 -- bytes written
;TI"File.read('test.txt')
;TI"# => "t--- data"
;T;0o;	;[I"O<b>The class is experimental and the interface is subject to change, this ;TI"Jis especially true of file mappings which may be removed entirely in ;TI"the future.</b>;T:
@fileI"io_buffer.c;T:0@omit_headings_from_table_of_contents_below0;0;0[�[U:RDoc::Constant[i�I"PAGE_SIZE;TI"IO::Buffer::PAGE_SIZE;T:public0o;;[o;	;[I"XThe operating system page size. Used for efficient page-aligned memory allocations.;T@;@~;0@~@cRDoc::NormalClass0U;[i�I"DEFAULT_SIZE;TI"IO::Buffer::DEFAULT_SIZE;T;0o;;[o;	;[I"MThe default buffer size, typically a (small) multiple of the PAGE_SIZE. ;TI"LCan be explicitly specified by setting the RUBY_IO_BUFFER_DEFAULT_SIZE ;TI"environment variable.;T@;@~;0@~@@�0U;[i�I"
EXTERNAL;TI"IO::Buffer::EXTERNAL;T;0o;;[o;	;[I"gIndicates that the memory in the buffer is owned by someone else. See #external? for more details.;T@;@~;0@~@@�0U;[i�I"
INTERNAL;TI"IO::Buffer::INTERNAL;T;0o;;[o;	;[I"eIndicates that the memory in the buffer is owned by the buffer. See #internal? for more details.;T@;@~;0@~@@�0U;[i�I"MAPPED;TI"IO::Buffer::MAPPED;T;0o;;[o;	;[I"nIndicates that the memory in the buffer is mapped by the operating system. See #mapped? for more details.;T@;@~;0@~@@�0U;[i�I"SHARED;TI"IO::Buffer::SHARED;T;0o;;[o;	;[I"�Indicates that the memory in the buffer is also mapped such that it can be shared with other processes. See #shared? for more details.;T@;@~;0@~@@�0U;[i�I"LOCKED;TI"IO::Buffer::LOCKED;T;0o;;[o;	;[I"|Indicates that the memory in the buffer is locked and cannot be resized or freed. See #locked? and #locked for more details.;T@;@~;0@~@@�0U;[i�I"PRIVATE;TI"IO::Buffer::PRIVATE;T;0o;;[o;	;[I"�Indicates that the memory in the buffer is mapped privately and changes won't be replicated to the underlying file. See #private? for more details.;T@;@~;0@~@@�0U;[i�I"
READONLY;TI"IO::Buffer::READONLY;T;0o;;[o;	;[I"{Indicates that the memory in the buffer is read only, and attempts to modify it will fail. See #readonly? for more details.;T@;@~;0@~@@�0U;[i�I"LITTLE_ENDIAN;TI"IO::Buffer::LITTLE_ENDIAN;T;0o;;[o;	;[I"{Refers to little endian byte order, where the least significant byte is stored first. See #get_value for more details.;T@;@~;0@~@@�0U;[i�I"BIG_ENDIAN;TI"IO::Buffer::BIG_ENDIAN;T;0o;;[o;	;[I"wRefers to big endian byte order, where the most significant byte is stored first. See #get_value for more details.;T@;@~;0@~@@�0U;[i�I"HOST_ENDIAN;TI"IO::Buffer::HOST_ENDIAN;T;0o;;[o;	;[I"SRefers to the byte order of the host machine. See #get_value for more details.;T@;@~;0@~@@�0U;[i�I"NETWORK_ENDIAN;TI"IO::Buffer::NETWORK_ENDIAN;T;0o;;[o;	;[I"dRefers to network byte order, which is the same as big endian. See #get_value for more details.;T@;@~;0@~@@�0[[I"Comparable;To;;[�;@~;0I"io_buffer.c;T[[I"
class;T[[;[
[I"for;T@�[I"map;T@�[I"new;T@�[I"size_of;T@�[I"string;T@�[:protected[�[:private[�[I"
instance;T[[;[1[I"&;T@�[I"<=>;T@�[I"^;T@�[I"|;T@�[I"~;T@�[I"	and!;T@�[I"
clear;T@�[I"	copy;T@�[I"	each;T@�[I"each_byte;T@�[I"empty?;T@�[I"external?;T@�[I"	free;T@�[I"get_string;T@�[I"get_value;T@�[I"get_values;T@�[I"hexdump;T@�[I"initialize_copy;T@�[I"inspect;T@�[I"internal?;T@�[I"locked;T@�[I"locked?;T@�[I"mapped?;T@�[I"	not!;T@�[I"
null?;T@�[I"or!;T@�[I"
pread;T@�[I"
private?;T@�[I"pwrite;T@�[I"	read;T@�[I"readonly?;T@�[I"resize;T@�[I"set_string;T@�[I"set_value;T@�[I"set_values;T@�[I"shared?;T@�[I"	size;T@�[I"
slice;T@�[I"	to_s;T@�[I"
transfer;T@�[I"valid?;T@�[I"values;T@�[I"
write;T@�[I"	xor!;T@�[;[�[;[�[�[U:RDoc::Context::Section[i�0o;;[�;0;0[I"ext/io/console/console.c;TI"IO;T@�