HTTP Parser
===========
[![Build Status](https://api.travis-ci.org/nodejs/http-parser.svg?branch=master)](https://travis-ci.org/nodejs/http-parser)
This is a parser for HTTP messages written in C. It parses both requests and
responses. The parser is designed to be used in performance HTTP
applications. It does not make any syscalls nor allocations, it does not
buffer data, it can be interrupted at anytime. Depending on your
architecture, it only requires about 40 bytes of data per message
stream (in a web server that is per connection).
Features:
* No dependencies
* Handles persistent streams (keep-alive).
* Decodes chunked encoding.
* Upgrade support
* Defends against buffer overflow attacks.
The parser extracts the following information from HTTP messages:
* Header fields and values
* Content-Length
* Request method
* Response status code
* Transfer-Encoding
* HTTP version
* Request URL
* Message body
Usage
-----
One `http_parser` object is used per TCP connection. Initialize the struct
using `http_parser_init()` and set the callbacks. That might look something
like this for a request parser:
```c
http_parser_settings settings;
settings.on_url = my_url_callback;
settings.on_header_field = my_header_field_callback;
/* ... */
http_parser *parser = malloc(sizeof(http_parser));
http_parser_init(parser, HTTP_REQUEST);
parser->data = my_socket;
```
When data is received on the socket execute the parser and check for errors.
```c
size_t len = 80*1024, nparsed;
char buf[len];
ssize_t recved;
recved = recv(fd, buf, len, 0);
if (recved < 0) {
/* Handle error. */
}
/* Start up / continue the parser.
* Note we pass recved==0 to signal that EOF has been received.
*/
nparsed = http_parser_execute(parser, &settings, buf, recved);
if (parser->upgrade) {
/* handle new protocol */
} else if (nparsed != recved) {
/* Handle error. Usually just close the connection. */
}
```
`http_parser` needs to know where the end of the stream is. For example, sometimes
servers send responses without Content-Length and expect the client to
consume input (for the body) until EOF. To tell `http_parser` about EOF, give
`0` as the fourth parameter to `http_parser_execute()`. Callbacks and errors
can still be encountered during an EOF, so one must still be prepared
to receive them.
Scalar valued message information such as `status_code`, `method`, and the
HTTP version are stored in the parser structure. This data is only
temporally stored in `http_parser` and gets reset on each new message. If
this information is needed later, copy it out of the structure during the
`headers_complete` callback.
The parser decodes the transfer-encoding for both requests and responses
transparently. That is, a chunked encoding is decoded before being sent to
the on_body callback.
The Special Problem of Upgrade
------------------------------
`http_parser` supports upgrading the connection to a different protocol. An
increasingly common example of this is the WebSocket protocol which sends
a request like
GET /demo HTTP/1.1
Upgrade: WebSocket
Connection: Upgrade
Host: example.com
Origin: http://example.com
WebSocket-Protocol: sample
followed by non-HTTP data.
(See [RFC6455](https://tools.ietf.org/html/rfc6455) for more information the
WebSocket protocol.)
To support this, the parser will treat this as a normal HTTP message without a
body, issuing both on_headers_complete and on_message_complete callbacks. However
http_parser_execute() will stop parsing at the end of the headers and return.
The user is expected to check if `parser->upgrade` has been set to 1 after
`http_parser_execute()` returns. Non-HTTP data begins at the buffer supplied
offset by the return value of `http_parser_execute()`.
Callbacks
---------
During the `http_parser_execute()` call, the callbacks set in
`http_parser_settings` will be executed. The parser maintains state and
never looks behind, so buffering the data is not necessary. If you need to
save certain data for later usage, you can do that from the callbacks.
There are two types of callbacks:
* notification `typedef int (*http_cb) (http_parser*);`
Callbacks: on_message_begin, on_headers_complete, on_message_complete.
* data `typedef int (*http_data_cb) (http_parser*, const char *at, size_t length);`
Callbacks: (requests only) on_url,
(common) on_header_field, on_header_value, on_body;
Callbacks must return 0 on success. Returning a non-zero value indicates
error to the parser, making it exit immediately.
For cases where it is necessary to pass local information to/from a callback,
the `http_parser` object's `data` field can be used.
An example of such a case is when using threads to handle a socket connection,
parse a request, and then give a response over that socket. By instantiation
of a thread-local struct containing relevant data (e.g. accepted socket,
allocated memory for callbacks to write into, etc), a parser's callbacks are
able to communicate data between the scope of the thread and the scope of the
callback in a threadsafe manner. This allows `http_parser` to be used in
multi-threaded contexts.
Example:
```c
typedef struct {
socket_t sock;
void* buffer;
int buf_len;
} custom_data_t;
int my_url_callback(http_parser* parser, const char *at, size_t length) {
/* access to thread local custom_data_t struct.
Use this access save parsed data for later use into thread local
buffer, or communicate over socket
*/
parser->data;
...
return 0;
}
...
void http_parser_thread(socket_t sock) {
int nparsed = 0;
/* allocate memory for user data */
custom_data_t *my_data = malloc(sizeof(custom_data_t));
/* some information for use by callbacks.
* achieves thread -> callback information flow */
my_data->sock = sock;
/* instantiate a thread-local parser */
http_parser *parser = malloc(sizeof(http_parser));
http_parser_init(parser, HTTP_REQUEST); /* initialise parser */
/* this custom data reference is accessible through the reference to the
parser supplied to callback functions */
parser->data = my_data;
http_parser_settings settings; /* set up callbacks */
settings.on_url = my_url_callback;
/* execute parser */
nparsed = http_parser_execute(parser, &settings, buf, recved);
...
/* parsed information copied from callback.
can now perform action on data copied into thread-local memory from callbacks.
achieves callback -> thread information flow */
my_data->buffer;
...
}
```
In case you parse HTTP message in chunks (i.e. `read()` request line
from socket, parse, read half headers, parse, etc) your data callbacks
may be called more than once. `http_parser` guarantees that data pointer is only
valid for the lifetime of callback. You can also `read()` into a heap allocated
buffer to avoid copying memory around if this fits your application.
Reading headers may be a tricky task if you read/parse headers partially.
Basically, you need to remember whether last header callback was field or value
and apply the following logic:
(on_header_field and on_header_value shortened to on_h_*)
------------------------ ------------ --------------------------------------------
| State (prev. callback) | Callback | Description/action |
------------------------ ------------ --------------------------------------------
| nothing (first call) | on_h_field | Allocate new buffer and copy callback data |
| | | into it |
------------------------ ------------ --------------------------------------------
| value | on_h_field | New header started. |
| | | Copy current name,value buffers to headers |
| | | list and allocate new buffer for new name |
------------------------ ---------
没有合适的资源?快使用搜索试试~ 我知道了~
aiohttp-3.6.0a2.tar.gz
0 下载量 144 浏览量
2024-06-15
23:54:06
上传
评论
收藏 1.06MB GZ 举报
温馨提示
Python库是一组预先编写的代码模块,旨在帮助开发者实现特定的编程任务,无需从零开始编写代码。这些库可以包括各种功能,如数学运算、文件操作、数据分析和网络编程等。Python社区提供了大量的第三方库,如NumPy、Pandas和Requests,极大地丰富了Python的应用领域,从数据科学到Web开发。Python库的丰富性是Python成为最受欢迎的编程语言之一的关键原因之一。这些库不仅为初学者提供了快速入门的途径,而且为经验丰富的开发者提供了强大的工具,以高效率、高质量地完成复杂任务。例如,Matplotlib和Seaborn库在数据可视化领域内非常受欢迎,它们提供了广泛的工具和技术,可以创建高度定制化的图表和图形,帮助数据科学家和分析师在数据探索和结果展示中更有效地传达信息。
资源推荐
资源详情
资源评论
收起资源包目录
aiohttp-3.6.0a2.tar.gz (300个子文件)
AUTHORS 2KB
make.bat 7KB
3579.bugfix 211B
3587.bugfix 178B
3595.bugfix 152B
3648.bugfix 134B
3621.bugfix 119B
3906.bugfix 95B
3880.bugfix 89B
3532.bugfix 88B
3628.bugfix 81B
3868.bugfix 79B
3576.bugfix 73B
3644.bugfix 66B
3631.bugfix 64B
3959.bugfix 61B
3818.bugfix 57B
3841.bugfix 55B
3614.bugfix 50B
3720.bugfix 50B
3660.bugfix 50B
3976.bugfix 45B
3633.bugfix 41B
_http_parser.c 974KB
_frozenlist.c 282KB
_http_writer.c 207KB
_helpers.c 204KB
_find_header.c 185KB
_websocket.c 133KB
test.c 117KB
http_parser.c 70KB
parsertrace.c 4KB
bench.c 4KB
url_parser.c 1KB
setup.cfg 1KB
build.cmd 838B
CODEOWNERS 572B
server.crt 1KB
server.csr 952B
3791.doc 85B
3526.doc 84B
3783.doc 61B
3775.doc 55B
3964.doc 53B
.editorconfig 346B
3798.feature 116B
3629.feature 115B
3980.feature 72B
.git 46B
.gitattributes 69B
.gitignore 687B
.gitignore 255B
.gitignore 12B
.gitmodules 125B
http_parser.gyp 3KB
hello.txt.gz 44B
http_parser.h 18KB
_find_header.h 170B
websocket.html 2KB
favicon.ico 4KB
MANIFEST.in 394B
tox.ini 1KB
pytest.ci.ini 223B
pytest.ini 184B
aiohttp.jpg 6KB
fuzzingclient.json 276B
fuzzingserver.json 217B
server.key 2KB
LICENSE-MIT 1KB
.mailmap 480B
Makefile 7KB
Makefile 5KB
Makefile 3KB
README.md 9KB
CODE_OF_CONDUCT.md 3KB
PULL_REQUEST_TEMPLATE.md 1KB
ISSUE_TEMPLATE.md 755B
PKG-INFO 20KB
PKG-INFO 20KB
old-logo.png 251KB
aiohttp.png 54KB
aiohttp-icon-128x128.png 4KB
_cparser.pxd 4KB
_find_header.pxd 68B
_headers.pxi 2KB
test_client_functional.py 80KB
test_connector.py 66KB
test_web_functional.py 56KB
client.py 43KB
test_multipart.py 42KB
connector.py 41KB
test_streams.py 39KB
test_client_request.py 39KB
test_client_response.py 39KB
test_urldispatch.py 39KB
web_urldispatcher.py 38KB
client_reqrep.py 35KB
test_web_response.py 33KB
multipart.py 32KB
test_http_parser.py 30KB
共 300 条
- 1
- 2
- 3
资源评论
程序员Chino的日记
- 粉丝: 3677
- 资源: 5万+
上传资源 快速赚钱
- 我的内容管理 展开
- 我的资源 快来上传第一个资源
- 我的收益 登录查看自己的收益
- 我的积分 登录查看自己的积分
- 我的C币 登录后查看C币余额
- 我的收藏
- 我的下载
- 下载帮助
最新资源
资源上传下载、课程学习等过程中有任何疑问或建议,欢迎提出宝贵意见哦~我们会及时处理!
点击此处反馈
安全验证
文档复制为VIP权益,开通VIP直接复制
信息提交成功