Zen

Translation

type: paragraph
In this section we describe the problem of modeling HTTP messages and explain how the library arrived at its solution, with a discussion of the benefits and drawbacks of the design choices. The goal for creating a message model is to create a container with value semantics, possibly movable and/or copyable, that contains all the information needed to serialize, or all of the information captured during parsing. More formally, given:
436/4360 · 436

Sign in to save translations.

Key English Chinese (Simplified Han script) Actions
HTTP Message Container __video__
HTTP Message Container __video__
The following video presentation was delivered at [@https://cppcon.org/ CppCon] in 2017. The presentation provides a simplified explanation of the design process for the HTTP message container used in Beast. The slides and code used are available in the [@https://github.com/vinniefalco/CppCon2017 GitHub repository].
The following video presentation was delivered at [@https://cppcon.org/ CppCon] in 2017. The presentation provides a simplified explanation of the design process for the HTTP message container used in Beast. The slides and code used are available in the [@https://github.com/vinniefalco/CppCon2017 GitHub repository].
In this section we describe the problem of modeling HTTP messages and explain how the library arrived at its solution, with a discussion of the benefits and drawbacks of the design choices. The goal for creating a message model is to create a container with value semantics, possibly movable and/or copyable, that contains all the information needed to serialize, or all of the information captured during parsing. More formally, given:
In this section we describe the problem of modeling HTTP messages and explain how the library arrived at its solution, with a discussion of the benefits and drawbacks of the design choices. The goal for creating a message model is to create a container with value semantics, possibly movable and/or copyable, that contains all the information needed to serialize, or all of the information captured during parsing. More formally, given:
* `m` is an instance of an HTTP message container
* `m` is an instance of an HTTP message container
* `x` is a series of octets describing a valid HTTP message in
* `x` is a series of octets describing a valid HTTP message in
* `S(m)` is a serialization function which produces a series of octets
* `S(m)` is a serialization function which produces a series of octets
* `P(x)` is a parsing function which produces a message container from
* `P(x)` is a parsing function which produces a message container from
These relations are true:
These relations are true:
* `S(m) == x`
* `S(m) == x`
* `P(S(m)) == m`
* `P(S(m)) == m`
We would also like our message container to have customization points permitting the following: allocator awareness, user-defined containers to represent header fields, and user-defined types and algorithms to represent the body. And finally, because requests and responses have different fields in the ['start-line], we would like the containers for requests and responses to be represented by different types for function overloading.
We would also like our message container to have customization points permitting the following: allocator awareness, user-defined containers to represent header fields, and user-defined types and algorithms to represent the body. And finally, because requests and responses have different fields in the ['start-line], we would like the containers for requests and responses to be represented by different types for function overloading.
Here is our first attempt at declaring some message containers:
Here is our first attempt at declaring some message containers:
These containers are capable of representing everything in the model of HTTP requests and responses described in __rfc7230__. Request and response objects are different types. The user can choose the container used to represent the fields. And the user can choose the [*Body] type, which is a concept defining not only the type of `body` member but also the algorithms used to transfer information in and out of that member when performing serialization and parsing.
These containers are capable of representing everything in the model of HTTP requests and responses described in __rfc7230__. Request and response objects are different types. The user can choose the container used to represent the fields. And the user can choose the [*Body] type, which is a concept defining not only the type of `body` member but also the algorithms used to transfer information in and out of that member when performing serialization and parsing.
However, a problem arises. How do we write a function which can accept an object that is either a request or a response? As written, the only obvious solution is to make the message a template type. Additional traits classes would then be needed to make sure that the passed object has a valid type which meets the requirements. These unnecessary complexities are bypassed by making each container a partial specialization: ``` /// An HTTP message template<bool isRequest, class Fields, class Body> struct message;
However, a problem arises. How do we write a function which can accept an object that is either a request or a response? As written, the only obvious solution is to make the message a template type. Additional traits classes would then be needed to make sure that the passed object has a valid type which meets the requirements. These unnecessary complexities are bypassed by making each container a partial specialization: ``` /// An HTTP message template<bool isRequest, class Fields, class Body> struct message;
/// An HTTP request template<class Fields, class Body> struct message<true, Fields, Body> {
/// An HTTP request template<class Fields, class Body> struct message<true, Fields, Body> {
126
};
};
/// An HTTP response template<bool isRequest, class Fields, class Body> struct message<false, Fields, Body> {
/// An HTTP response template<bool isRequest, class Fields, class Body> struct message<false, Fields, Body> {
138
}; ```
}; ```
English Chinese (Simplified Han script) Actions
The following video presentation was delivered at [@https://cppcon.org/ CppCon] in 2017. The presentation provides a simplified explanation of the design process for the HTTP message container used in Beast. The slides and code used are available in the [@https://github.com/vinniefalco/CppCon2017 GitHub repository].
The following video presentation was delivered at [@https://cppcon.org/ CppCon] in 2017. The presentation provides a simplified explanation of the design process for the HTTP message container used in Beast. The slides and code used are available in the [@https://github.com/vinniefalco/CppCon2017 GitHub repository].
This function can manipulate the fields common to requests and responses. If it needs to access the other fields, it can use overloads with partial specialization, or in C++17 a `constexpr` expression: ``` template<bool isRequest, class Fields, class Body> void f(message<isRequest, Fields, Body>& msg) {
This function can manipulate the fields common to requests and responses. If it needs to access the other fields, it can use overloads with partial specialization, or in C++17 a `constexpr` expression: ``` template<bool isRequest, class Fields, class Body> void f(message<isRequest, Fields, Body>& msg) {
} ```
} ```
HTTP Message Container __video__
HTTP Message Container __video__
In this section we describe the problem of modeling HTTP messages and explain how the library arrived at its solution, with a discussion of the benefits and drawbacks of the design choices. The goal for creating a message model is to create a container with value semantics, possibly movable and/or copyable, that contains all the information needed to serialize, or all of the information captured during parsing. More formally, given:
In this section we describe the problem of modeling HTTP messages and explain how the library arrived at its solution, with a discussion of the benefits and drawbacks of the design choices. The goal for creating a message model is to create a container with value semantics, possibly movable and/or copyable, that contains all the information needed to serialize, or all of the information captured during parsing. More formally, given:
* `m` is an instance of an HTTP message container
* `m` is an instance of an HTTP message container
* `x` is a series of octets describing a valid HTTP message in
* `x` is a series of octets describing a valid HTTP message in
* `S(m)` is a serialization function which produces a series of octets
* `S(m)` is a serialization function which produces a series of octets
* `P(x)` is a parsing function which produces a message container from
* `P(x)` is a parsing function which produces a message container from
These relations are true:
These relations are true:
* `S(m) == x`
* `S(m) == x`
* `P(S(m)) == m`
* `P(S(m)) == m`
We would also like our message container to have customization points permitting the following: allocator awareness, user-defined containers to represent header fields, and user-defined types and algorithms to represent the body. And finally, because requests and responses have different fields in the ['start-line], we would like the containers for requests and responses to be represented by different types for function overloading.
We would also like our message container to have customization points permitting the following: allocator awareness, user-defined containers to represent header fields, and user-defined types and algorithms to represent the body. And finally, because requests and responses have different fields in the ['start-line], we would like the containers for requests and responses to be represented by different types for function overloading.
Here is our first attempt at declaring some message containers:
Here is our first attempt at declaring some message containers:
These containers are capable of representing everything in the model of HTTP requests and responses described in __rfc7230__. Request and response objects are different types. The user can choose the container used to represent the fields. And the user can choose the [*Body] type, which is a concept defining not only the type of `body` member but also the algorithms used to transfer information in and out of that member when performing serialization and parsing.
These containers are capable of representing everything in the model of HTTP requests and responses described in __rfc7230__. Request and response objects are different types. The user can choose the container used to represent the fields. And the user can choose the [*Body] type, which is a concept defining not only the type of `body` member but also the algorithms used to transfer information in and out of that member when performing serialization and parsing.
However, a problem arises. How do we write a function which can accept an object that is either a request or a response? As written, the only obvious solution is to make the message a template type. Additional traits classes would then be needed to make sure that the passed object has a valid type which meets the requirements. These unnecessary complexities are bypassed by making each container a partial specialization: ``` /// An HTTP message template<bool isRequest, class Fields, class Body> struct message;
However, a problem arises. How do we write a function which can accept an object that is either a request or a response? As written, the only obvious solution is to make the message a template type. Additional traits classes would then be needed to make sure that the passed object has a valid type which meets the requirements. These unnecessary complexities are bypassed by making each container a partial specialization: ``` /// An HTTP message template<bool isRequest, class Fields, class Body> struct message;
/// An HTTP request template<class Fields, class Body> struct message<true, Fields, Body> {
/// An HTTP request template<class Fields, class Body> struct message<true, Fields, Body> {
The start-line data members are replaced by traditional accessors using non-owning references to string buffers. The method is stored using a simple integer instead of the entire string, for the case where the method is recognized from the set of known verb strings.
The start-line data members are replaced by traditional accessors using non-owning references to string buffers. The method is stored using a simple integer instead of the entire string, for the case where the method is recognized from the set of known verb strings.
Now we add a requirement to the fields type: management of the corresponding string is delegated to the [*Fields] container, which can already be allocator aware and constructed with the necessary allocator parameter via the provided constructor overloads for `message`. The delegation implementation looks like this (only the response header specialization is shown): ``` /// An HTTP response header template<class Fields> struct header<false, Fields> : Fields {
Now we add a requirement to the fields type: management of the corresponding string is delegated to the [*Fields] container, which can already be allocator aware and constructed with the necessary allocator parameter via the provided constructor overloads for `message`. The delegation implementation looks like this (only the response header specialization is shown): ``` /// An HTTP response header template<class Fields> struct header<false, Fields> : Fields {

Loading…

User avatar admin

String added in the repository
In this section we describe the problem of modeling HTTP messages and explain how the library arrived at its solution, with a discussion of the benefits and drawbacks of the design choices. The goal for creating a message model is to create a container with value semantics, possibly movable and/or copyable, that contains all the information needed to serialize, or all of the information captured during parsing. More formally, given:
In this section we describe the problem of modeling HTTP messages and explain how the library arrived at its solution, with a discussion of the benefits and drawbacks of the design choices. The goal for creating a message model is to create a container with value semantics, possibly movable and/or copyable, that contains all the information needed to serialize, or all of the information captured during parsing. More formally, given:
06/05/2026
Browse all string changes

Things to check

Unchanged translation

Source and translation are identical.

Reset

Glossary

English Chinese (Simplified Han script)
No related strings found in the glossary.

String information

Source string description
type: paragraph
Unit identifier
59308
Source string location
string ID 31
String age
06/05/2026
Last updated
06/05/2026
Source string age
06/05/2026
Translation file QuickBook file
doc/qbk/08_design/1_http_message_zh_Hans.qbk, string 3