"PHP Kernel Learning" sapi____php

Brother Bird's blog mentioned SAPI, I also look at the source.

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PHP architecture diagram (photo from http://stblog.baidu-tech.com/?p=763):

Middle-tier (SAPI) decoupling of Web server and PHP

Each SAPI implementation is a _SAPI_MODULE_STRUCT structure:

In the PHP source directory with the Grep-r _sapi_module_struct search to its definition in main/sapi.h:

struct _sapi_module_struct {char *name;

    Char *pretty_name;
    Int (*startup) (struct _sapi_module_struct *sapi_module);

    Int (*shutdown) (struct _sapi_module_struct *sapi_module);
    Int (*activate) (tsrmls_d);

    Int (*deactivate) (tsrmls_d);
    Int (*ub_write) (const char *STR, unsigned int str_length tsrmls_dc);
    void (*flush) (void *server_context);
    struct stat * (*get_stat) (tsrmls_d);

    char * (*getenv) (char *name, size_t name_len tsrmls_dc);

    void (*sapi_error) (int type, const char *error_msg, ...); Int (*header_handler) (Sapi_header_struct *sapi_header, Sapi_header_op_enum op, sapi_headers_struct *sapi_headers
    TSRMLS_DC);
    Int (*send_headers) (sapi_headers_struct *sapi_headers tsrmls_dc);

    void (*send_header) (Sapi_header_struct *sapi_header, void *server_context tsrmls_dc);
    Int (*read_post) (char *buffer, uint count_bytes tsrmls_dc);

    char * (*read_cookies) (tsrmls_d); void (*register_server_variables) (Zval *track_vars_array tsrmls_dc);
    void (*log_message) (char *message tsrmls_dc);
    Double (*get_request_time) (tsrmls_d);

    void (*terminate_process) (tsrmls_d);

    Char *php_ini_path_override;
    void (*block_interruptions) (void);

    void (*unblock_interruptions) (void);
    void (*default_post_reader) (tsrmls_d);
    void (*treat_data) (int arg, char *str, zval *destarray tsrmls_dc);

    Char *executable_location;
    int Php_ini_ignore; int php_ini_ignore_cwd;

    /* Don t look for php.ini in the current directory * * INT (*GET_FD) (int *fd tsrmls_dc);

    Int (*force_http_10) (tsrmls_d);
    Int (*get_target_uid) (uid_t * tsrmls_dc);
    Int (*get_target_gid) (gid_t * tsrmls_dc);

    unsigned int (*input_filter) (int arg, char *var, char **val, unsigned int val_len, unsigned int *new_val_len tsrmls_dc);
    void (*ini_defaults) (HashTable *configuration_hash);

    int phpinfo_as_text;
    Char *ini_entries;
    Const Zend_function_entry *additional_functions; unsigned int (*input_filter_init) (tsrmls_d);
 };

Below, take Cgi_sapi as an example to illustrate the implementation of SAPI:

Static Sapi_module_struct Cgi_sapi_module = {"cgi-fcgi",/* name */"cgi/fastcgi", /* Pretty name */php_cgi_startup,/* Startup when SAPI initialization, first call the function * * Php_module_shutdown_wra Pper,/* Shutdown closes the function wrapper, which is used to release all the SAPI data structure, memory, etc./sapi_cgi_activate,/* Activate this function will be invoked at the start of each request and it will

    The data structure before each request is initialized/* sapi_cgi_deactivate,/* Deactivate this function is invoked at the end of each request, to ensure that all data is available, and to release a data structure initialized in activate.                 Sapi_cgi_ub_write,/* unbuffered write does not cache writes (unbuffered write), which is used to output PHP data to the client * * Sapi_cgi_flush, /* Flush refresh output, in CLI mode by using the C language library function Fflush implement/NULL,/* Get UID/* sapi_cgi                           _getenv,/* getenv * * php_error,/* ERROR handler/NULL,                           /* Header handler/sapi_cgi_send_headers,/* Send headers Handler sending header information * * NULL, /* Send HeaDer Handler/Sapi_cgi_read_post,/* Read post data when the requested method is post, the program will operate $_post, $HTTP _raw_post_data variables * * Sapi_cgi_read_cookies, * Read cookies when SAPI is activated, the program calls this function and assigns the value obtained by this function to the SG (request_info). cookie_data*/SAP I_cgi_register_variables,/* Register server variables/sapi_cgi_log_message,/* Log message/* NUL L,/* GET request time */NULL,/* Child terminate */Standar
 D_sapi_module_properties};

Through the above CGI example, we can see that the entire SAPI is similar to an Object-oriented template method pattern application. Some functions contained in SAPI.C and SAPI.h files are abstract templates in template method patterns, and each server's definition and related implementation of Sapi_module is a specific template.

Reference:

1.http://stblog.baidu-tech.com/?p=763

2.http://www.laruence.com/2008/08/12/180.html

3.http://www.nowamagic.net/librarys/veda/detail/1292