msgid "" msgstr "" "Project-Id-Version: Chinese (Simplified Han script) (Boost Beast Translation " "(zh_Hans))\n" "Report-Msgid-Bugs-To: \n" "POT-Creation-Date: 2026-06-07 11:02+0000\n" "PO-Revision-Date: YEAR-MO-DA HO:MI+ZONE\n" "Last-Translator: FULL NAME \n" "Language-Team: Chinese (Simplified Han script) \n" "Language: zh_Hans\n" "MIME-Version: 1.0\n" "Content-Type: text/plain; charset=UTF-8\n" "Content-Transfer-Encoding: 8bit\n" "Plural-Forms: nplurals=1; plural=0;\n" "X-Generator: Weblate 2026.5\n" #. type: section title #: 10 #, fuzzy msgid "Timeouts __example__" msgstr "Timeouts __example__" #. type: paragraph #: 12 #, fuzzy msgid "" "Network programs must handle adverse connection conditions; the most common " "is that a connected peer goes offline unexpectedly. Protocols have no way of " "identifying this reliably: the peer is offline after all, and unable to send " "a message announcing the absence. A peer can go offline for various reasons:" msgstr "" "Network programs must handle adverse connection conditions; the most common " "is that a connected peer goes offline unexpectedly. Protocols have no way of " "identifying this reliably: the peer is offline after all, and unable to send " "a message announcing the absence. A peer can go offline for various reasons:" #. type: paragraph #: 24 #, fuzzy msgid "" "To determine when a peer is offline or idle, a program will implement a " "[@https://en.wikipedia.org/wiki/Timeout_(computing) timeout] algorithm, " "which closes the connection after a specified amount of time if some " "condition is met. For example, if no data is received for the duration. A " "timeout may be used to:" msgstr "" "To determine when a peer is offline or idle, a program will implement a " "[@https://en.wikipedia.org/wiki/Timeout_(computing) timeout] algorithm, " "which closes the connection after a specified amount of time if some " "condition is met. For example, if no data is received for the duration. A " "timeout may be used to:" #. type: paragraph #: 36 #, fuzzy msgid "" "Traditionally, programs use a [@boost:/doc/html/boost_asio/reference/" "steady_timer.html `net::steady_timer`] to determine when a timeout occurs, " "and then call [@boost:/doc/html/boost_asio/reference/basic_socket/close/" "overload2.html `close`] on the socket to release the resources. The " "complexity of managing a separate timer is often a source of [@http://" "www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p1269r0.html#timers " "frustration] for non-experts." msgstr "" "Traditionally, programs use a [@boost:/doc/html/boost_asio/reference/" "steady_timer.html `net::steady_timer`] to determine when a timeout occurs, " "and then call [@boost:/doc/html/boost_asio/reference/basic_socket/close/" "overload2.html `close`] on the socket to release the resources. The " "complexity of managing a separate timer is often a source of [@http://" "www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p1269r0.html#timers " "frustration] for non-experts." #. type: paragraph #: 46 #, fuzzy msgid "For portability reasons, networking does not provide timeouts" msgstr "For portability reasons, networking does not provide timeouts" #. type: paragraph #: 50 #, fuzzy msgid "" "To simplify the handling of timeouts, these provided types wrap a [@boost:/" "doc/html/boost_asio/reference/basic_stream_socket.html " "`net::basic_stream_socket`] to provide additional features:" msgstr "" "To simplify the handling of timeouts, these provided types wrap a [@boost:/" "doc/html/boost_asio/reference/basic_stream_socket.html " "`net::basic_stream_socket`] to provide additional features:" #. type: table cell #: 54 #, fuzzy msgid "[link beast.ref.boost__beast__tcp_stream `tcp_stream`]" msgstr "[link beast.ref.boost__beast__tcp_stream `tcp_stream`]" #. type: table cell #: 54 #, fuzzy msgid "" "[itemized_list [Timeouts for logical operations] [[@boost:/doc/html/" "boost_asio/reference/ip__tcp.html `net::ip::tcp`] protocol] [[@boost:/doc/" "html/boost_asio/reference/executor.html `net::executor`] executor] [[link " "beast.ref.boost__beast__unlimited_rate_policy `unlimited_rate_policy`] rate " "limits] ]" msgstr "" "[itemized_list [Timeouts for logical operations] [[@boost:/doc/html/" "boost_asio/reference/ip__tcp.html `net::ip::tcp`] protocol] [[@boost:/doc/" "html/boost_asio/reference/executor.html `net::executor`] executor] [[link " "beast.ref.boost__beast__unlimited_rate_policy `unlimited_rate_policy`] rate " "limits] ]" #. type: table cell #: 54 #, fuzzy msgid "[link beast.ref.boost__beast__basic_stream `basic_stream`]" msgstr "[link beast.ref.boost__beast__basic_stream `basic_stream`]" #. type: table cell #: 54 #, fuzzy msgid "" "[itemized_list [Timeouts for logical operations] [Configurable __Protocol__ " "type] [Configurable __Executor__ type] [Configurable __RatePolicy__ type] ]" msgstr "" "[itemized_list [Timeouts for logical operations] [Configurable __Protocol__ " "type] [Configurable __Executor__ type] [Configurable __RatePolicy__ type] ]" #. type: heading #: 76 #, fuzzy msgid "Construction" msgstr "Construction" #. type: paragraph #: 78 #, fuzzy msgid "" "The `tcp_stream` is designed as a replacement for [@boost:/doc/html/" "boost_asio/reference/ip__tcp/socket.html `net::ip::tcp::socket`]. Any " "program which currently uses a socket, can switch to a `tcp_stream` and " "achieve the features above (although some interfaces are different, see " "below). Networking now allows I/O objects to construct with any instance of " "__ExecutionContext__ or __Executor__ objects. Here we construct a stream " "which uses a particular I/O context to dispatch completion handlers:" msgstr "" "The `tcp_stream` is designed as a replacement for [@boost:/doc/html/" "boost_asio/reference/ip__tcp/socket.html `net::ip::tcp::socket`]. Any " "program which currently uses a socket, can switch to a `tcp_stream` and " "achieve the features above (although some interfaces are different, see " "below). Networking now allows I/O objects to construct with any instance of " "__ExecutionContext__ or __Executor__ objects. Here we construct a stream " "which uses a particular I/O context to dispatch completion handlers:" #. type: paragraph #: 88 #, fuzzy msgid "Alternatively, we can construct the stream from an executor:" msgstr "Alternatively, we can construct the stream from an executor:" #. type: paragraph #: 92 #, fuzzy msgid "" "The function [@boost:/doc/html/boost_asio/reference/make_strand.html " "`make_strand`] returns a strand constructed from an execution context or " "executor. When a [@boost:/doc/html/boost_asio/reference/strand.html " "`net::strand`] is chosen for the stream's executor, all completion handlers " "which do not already have an associated executor will use the strand. This " "is both a notational convenience (no need for `strand::wrap` or " "`bind_executor` at call sites) and a measure of safety, as it is no longer " "possible to forget to use the strand." msgstr "" "The function [@boost:/doc/html/boost_asio/reference/make_strand.html " "`make_strand`] returns a strand constructed from an execution context or " "executor. When a [@boost:/doc/html/boost_asio/reference/strand.html " "`net::strand`] is chosen for the stream's executor, all completion handlers " "which do not already have an associated executor will use the strand. This " "is both a notational convenience (no need for `strand::wrap` or " "`bind_executor` at call sites) and a measure of safety, as it is no longer " "possible to forget to use the strand." #. type: heading #: 106 #, fuzzy msgid "Connecting" msgstr "Connecting" #. type: paragraph #: 108 #, fuzzy msgid "" "Before data can be exchanged, the stream needs to be connected to a peer. " "The following code sets a timeout for an asynchronous connect operation. In " "Beast, functions to connect to a range of endpoints (such as the range " "returned by [@boost:/doc/html/boost_asio/reference/ip__basic_resolver/" "resolve/overload3.html `net::ip::tcp::resolver::resolve`]) are members of " "the class rather than free functions such as [@boost:/doc/html/boost_asio/" "reference/async_connect.html `net::async_connect`]." msgstr "" "Before data can be exchanged, the stream needs to be connected to a peer. " "The following code sets a timeout for an asynchronous connect operation. In " "Beast, functions to connect to a range of endpoints (such as the range " "returned by [@boost:/doc/html/boost_asio/reference/ip__basic_resolver/" "resolve/overload3.html `net::ip::tcp::resolver::resolve`]) are members of " "the class rather than free functions such as [@boost:/doc/html/boost_asio/" "reference/async_connect.html `net::async_connect`]." #. type: paragraph #: 118 #, fuzzy msgid "" "A server will use an acceptor bound to a particular IP address and port to " "listen to and receive incoming connection requests. The acceptor returns an " "ordinary socket. A `tcp_stream` can be move-constructed from the underlying " "`basic_stream_socket` thusly:" msgstr "" "A server will use an acceptor bound to a particular IP address and port to " "listen to and receive incoming connection requests. The acceptor returns an " "ordinary socket. A `tcp_stream` can be move-constructed from the underlying " "`basic_stream_socket` thusly:" #. type: heading #: 127 #, fuzzy msgid "Reading and Writing" msgstr "Reading and Writing" #. type: paragraph #: 129 #, fuzzy msgid "" "Timeouts apply to the logical operation, expressed as a series of " "asynchronous calls, rather than just the next call. This code reads a line " "from the stream and writes it back. Both the read and the write must " "complete within 30 seconds from when the timeout was set; the timer is not " "reset between operations." msgstr "" "Timeouts apply to the logical operation, expressed as a series of " "asynchronous calls, rather than just the next call. This code reads a line " "from the stream and writes it back. Both the read and the write must " "complete within 30 seconds from when the timeout was set; the timer is not " "reset between operations." #. type: paragraph #: 136 #, fuzzy msgid "" "Since reads and writes can take place concurrently, it is possible to have " "two simultaneous logical operations where each operation either only reads, " "or only writes. The beginning of a new read or write operation will use the " "most recently set timeout. This will not affect operations that are already " "outstanding." msgstr "" "Since reads and writes can take place concurrently, it is possible to have " "two simultaneous logical operations where each operation either only reads, " "or only writes. The beginning of a new read or write operation will use the " "most recently set timeout. This will not affect operations that are already " "outstanding." #. type: paragraph #: 144 #, fuzzy msgid "" "When a timeout is set, it cancels any previous read or write timeout for " "which no outstanding operation is in progress. Algorithms which loop over " "logical operations simply need to set the timeout once before the logical " "operation, it is not necessary to call `expires_never` in this case. Here we " "implement an algorithm which continuously echoes lines back, with a timeout. " "This example is implemented as a complete function." msgstr "" "When a timeout is set, it cancels any previous read or write timeout for " "which no outstanding operation is in progress. Algorithms which loop over " "logical operations simply need to set the timeout once before the logical " "operation, it is not necessary to call `expires_never` in this case. Here we " "implement an algorithm which continuously echoes lines back, with a timeout. " "This example is implemented as a complete function." #. type: heading #: 155 #, fuzzy msgid "https_get" msgstr "https_get" #. type: paragraph #: 157 #, fuzzy msgid "" "It is important to note that all of the examples thus far which perform " "reads and writes with a timeout, make use of the existing networking stream " "algorithms. As these algorithms are written generically to work with any " "object meeting the stream requirements, they transparently support timeouts " "when used with `tcp_stream`. This can be used to enable timeouts for stream " "wrappers that do not currently support timeouts." msgstr "" "It is important to note that all of the examples thus far which perform " "reads and writes with a timeout, make use of the existing networking stream " "algorithms. As these algorithms are written generically to work with any " "object meeting the stream requirements, they transparently support timeouts " "when used with `tcp_stream`. This can be used to enable timeouts for stream " "wrappers that do not currently support timeouts." #. type: paragraph #: 164 #, fuzzy msgid "" "The following code establishes an encrypted connection, writes an HTTP " "request, reads the HTTP response, and closes the connection gracefully. If " "these operations take longer than 30 seconds total, a timeout occurs. This " "code is intended to show how `tcp_stream` can be used to enable timeouts " "across unmodified stream algorithms which were not originally written to " "support timing out, and how a blocking algorithm may be written from " "asynchronous intermediate operations." msgstr "" "The following code establishes an encrypted connection, writes an HTTP " "request, reads the HTTP response, and closes the connection gracefully. If " "these operations take longer than 30 seconds total, a timeout occurs. This " "code is intended to show how `tcp_stream` can be used to enable timeouts " "across unmodified stream algorithms which were not originally written to " "support timing out, and how a blocking algorithm may be written from " "asynchronous intermediate operations." #. type: section title #: 178 #, fuzzy msgid "Rate Limiting __example__" msgstr "Rate Limiting __example__" #. type: paragraph #: 180 #, fuzzy msgid "" "The [link beast.ref.boost__beast__basic_stream `basic_stream`] class " "template supports an additional `RatePolicy` template parameter. Objects of " "this type must meet the requirements of __RatePolicy__. They are used to " "implement rate limiting or bandwidth management. The default policy for " "`basic_stream` and `tcp_stream` is [link " "beast.ref.boost__beast__unlimited_rate_policy `unlimited_rate_policy`], " "which places no limits on reading and writing. The library comes with the " "[link beast.ref.boost__beast__simple_rate_policy `simple_rate_policy`], " "allowing for independent control of read and write limits expressed in terms " "of bytes per second. The follow code creates an instance of the basic stream " "with a simple rate policy, and sets the read and write limits:" msgstr "" "The [link beast.ref.boost__beast__basic_stream `basic_stream`] class " "template supports an additional `RatePolicy` template parameter. Objects of " "this type must meet the requirements of __RatePolicy__. They are used to " "implement rate limiting or bandwidth management. The default policy for " "`basic_stream` and `tcp_stream` is [link " "beast.ref.boost__beast__unlimited_rate_policy `unlimited_rate_policy`], " "which places no limits on reading and writing. The library comes with the " "[link beast.ref.boost__beast__simple_rate_policy `simple_rate_policy`], " "allowing for independent control of read and write limits expressed in terms " "of bytes per second. The follow code creates an instance of the basic stream " "with a simple rate policy, and sets the read and write limits:" #. type: paragraph #: 195 #, fuzzy msgid "" "More sophisticated rate policies can be implemented as user-defined types " "which meet the requirements of __RatePolicy__. Here, we develop a rate " "policy that measures the instantaneous throughput of reads and writes. First " "we write a small utility class that applies an exponential smoothing " "function to a series of discrete rate samples, to calculate instantaneous " "throughput." msgstr "" "More sophisticated rate policies can be implemented as user-defined types " "which meet the requirements of __RatePolicy__. Here, we develop a rate " "policy that measures the instantaneous throughput of reads and writes. First " "we write a small utility class that applies an exponential smoothing " "function to a series of discrete rate samples, to calculate instantaneous " "throughput." #. type: paragraph #: 203 #, fuzzy msgid "" "Then we define our rate policy object. We friend the type [link " "beast.ref.boost__beast__rate_policy_access `rate_policy_access`] to allow " "our implementation to be private, but still allow the `basic_stream` access " "to call the required functions. This lets us avoid having to write a " "cumbersome friend declaration for the `basic_stream` class template. Public " "members of rate policy objects become part of the stream object's interface, " "through a call to `rate_policy`." msgstr "" "Then we define our rate policy object. We friend the type [link " "beast.ref.boost__beast__rate_policy_access `rate_policy_access`] to allow " "our implementation to be private, but still allow the `basic_stream` access " "to call the required functions. This lets us avoid having to write a " "cumbersome friend declaration for the `basic_stream` class template. Public " "members of rate policy objects become part of the stream object's interface, " "through a call to `rate_policy`." #. type: paragraph #: 213 #, fuzzy msgid "" "To use our new policy we declare an instance of the stream, and then use it " "with stream algorithms as usual. At any time, we can determine the current " "read or write rates by calling into the policy." msgstr "" "To use our new policy we declare an instance of the stream, and then use it " "with stream algorithms as usual. At any time, we can determine the current " "read or write rates by calling into the policy."