http_protocol.h

Apache HTTP Server 是一个功能强大的灵活的与HTTP/1.1相兼容的web服务器.这里给出的是Apache HTTP服务器的源码。

 * @param r The current request
 * @return The number of bytes sent
 * @deffunc int ap_rwrite(const void *buf, int nbyte, request_rec *r)
 */
AP_DECLARE(int) ap_rwrite(const void *buf, int nbyte, request_rec *r);

/**
 * Write an unspecified number of strings to the request
 * @param r The current request
 * @param ... The strings to write
 * @return The number of bytes sent
 * @deffunc int ap_rvputs(request_rec *r, ...)
 */
AP_DECLARE_NONSTD(int) ap_rvputs(request_rec *r,...);

/**
 * Output data to the client in a printf format
 * @param r The current request
 * @param fmt The format string
 * @param vlist The arguments to use to fill out the format string
 * @return The number of bytes sent
 * @deffunc int ap_vrprintf(request_rec *r, const char *fmt, va_list vlist)
 */
AP_DECLARE(int) ap_vrprintf(request_rec *r, const char *fmt, va_list vlist);

/**
 * Output data to the client in a printf format
 * @param r The current request
 * @param fmt The format string
 * @param ... The arguments to use to fill out the format string
 * @return The number of bytes sent
 * @deffunc int ap_rprintf(request_rec *r, const char *fmt, ...)
 */
AP_DECLARE_NONSTD(int) ap_rprintf(request_rec *r, const char *fmt,...)
				__attribute__((format(printf,2,3)));
/**
 * Flush all of the data for the current request to the client
 * @param r The current request
 * @return The number of bytes sent
 * @deffunc int ap_rflush(request_rec *r)
 */
AP_DECLARE(int) ap_rflush(request_rec *r);

/**
 * Index used in custom_responses array for a specific error code
 * (only use outside protocol.c is in getting them configured).
 * @param status HTTP status code
 * @return The index of the response
 * @deffunc int ap_index_of_response(int status)
 */
AP_DECLARE(int) ap_index_of_response(int status);

/** 
 * Return the Status-Line for a given status code (excluding the
 * HTTP-Version field). If an invalid or unknown status code is
 * passed, "500 Internal Server Error" will be returned. 
 * @param status The HTTP status code
 * @return The Status-Line
 * @deffunc const char *ap_get_status_line(int status)
 */
AP_DECLARE(const char *) ap_get_status_line(int status);

/* Reading a block of data from the client connection (e.g., POST arg) */

/**
 * Setup the client to allow Apache to read the request body.
 * @param r The current request
 * @param read_policy How the server should interpret a chunked 
 *                    transfer-encoding.  One of: <pre>
 *    REQUEST_NO_BODY          Send 413 error if message has any body
 *    REQUEST_CHUNKED_ERROR    Send 411 error if body without Content-Length
 *    REQUEST_CHUNKED_DECHUNK  If chunked, remove the chunks for me.
 * </pre>
 * @return either OK or an error code
 * @deffunc int ap_setup_client_block(request_rec *r, int read_policy)
 */
AP_DECLARE(int) ap_setup_client_block(request_rec *r, int read_policy);

/**
 * Determine if the client has sent any data.  This also sends a 
 * 100 Continue response to HTTP/1.1 clients, so modules should not be called
 * until the module is ready to read content.
 * @warning Never call this function more than once.
 * @param r The current request
 * @return 0 if there is no message to read, 1 otherwise
 * @deffunc int ap_should_client_block(request_rec *r)
 */
AP_DECLARE(int) ap_should_client_block(request_rec *r);

/**
 * Call this in a loop.  It will put data into a buffer and return the length
 * of the input block
 * @param r The current request
 * @param buffer The buffer in which to store the data
 * @param bufsiz The size of the buffer
 * @return Number of bytes inserted into the buffer.  When done reading, 0
 *         if EOF, or -1 if there was an error
 * @deffunc long ap_get_client_block(request_rec *r, char *buffer, apr_size_t bufsiz)
 */
AP_DECLARE(long) ap_get_client_block(request_rec *r, char *buffer, apr_size_t bufsiz);

/**
 * In HTTP/1.1, any method can have a body.  However, most GET handlers
 * wouldn't know what to do with a request body if they received one.
 * This helper routine tests for and reads any message body in the request,
 * simply discarding whatever it receives.  We need to do this because
 * failing to read the request body would cause it to be interpreted
 * as the next request on a persistent connection.
 * @param r The current request
 * @return error status if request is malformed, OK otherwise 
 * @deffunc int ap_discard_request_body(request_rec *r)
 */
AP_DECLARE(int) ap_discard_request_body(request_rec *r);


/**
 * Setup the output headers so that the client knows how to authenticate
 * itself the next time, if an authentication request failed.  This function
 * works for both basic and digest authentication
 * @param r The current request
 * @deffunc void ap_note_auth_failure(request_rec *r)
 */ 
AP_DECLARE(void) ap_note_auth_failure(request_rec *r);

/**
 * Setup the output headers so that the client knows how to authenticate
 * itself the next time, if an authentication request failed.  This function
 * works only for basic authentication
 * @param r The current request
 * @deffunc void ap_note_basic_auth_failure(request_rec *r)
 */ 
AP_DECLARE(void) ap_note_basic_auth_failure(request_rec *r);

/**
 * Setup the output headers so that the client knows how to authenticate
 * itself the next time, if an authentication request failed.  This function
 * works only for digest authentication
 * @param r The current request
 * @deffunc void ap_note_digest_auth_failure(request_rec *r)
 */ 
AP_DECLARE(void) ap_note_digest_auth_failure(request_rec *r);

/**
 * Get the password from the request headers
 * @param r The current request
 * @param pw The password as set in the headers
 * @return 0 (OK) if it set the 'pw' argument (and assured
 *         a correct value in r->user); otherwise it returns 
 *         an error code, either HTTP_INTERNAL_SERVER_ERROR if things are 
 *         really confused, HTTP_UNAUTHORIZED if no authentication at all 
 *         seemed to be in use, or DECLINED if there was authentication but 
 *         it wasn't Basic (in which case, the caller should presumably 
 *         decline as well).
 * @deffunc int ap_get_basic_auth_pw(request_rec *r, const char **pw)
 */
AP_DECLARE(int) ap_get_basic_auth_pw(request_rec *r, const char **pw);

/**
 * parse_uri: break apart the uri
 * @warning Side Effects: <pre>
 *    - sets r->args to rest after '?' (or NULL if no '?')
 *    - sets r->uri to request uri (without r->args part)
 *    - sets r->hostname (if not set already) from request (scheme://host:port)
 * </pre>
 * @param r The current request
 * @param uri The uri to break apart
 * @deffunc void ap_parse_uri(request_rec *r, const char *uri)
 */
AP_CORE_DECLARE(void) ap_parse_uri(request_rec *r, const char *uri);

/**
 * Get the next line of input for the request
 * @param s The buffer into which to read the line
 * @param n The size of the buffer
 * @param r The request
 * @param fold Whether to merge continuation lines
 * @return The length of the line, if successful
 *         n, if the line is too big to fit in the buffer
 *         -1 for miscellaneous errors
 * @deffunc int ap_method_number_of(const char *method)
 */
AP_DECLARE(int) ap_getline(char *s, int n, request_rec *r, int fold);

/**
 * Get the next line of input for the request
 *
 * Note: on ASCII boxes, ap_rgetline is a macro which simply calls 
 *       ap_rgetline_core to get the line of input.
 * 
 *       on EBCDIC boxes, ap_rgetline is a wrapper function which
 *       translates ASCII protocol lines to the local EBCDIC code page
 *       after getting the line of input.
 *       
 * @param s Pointer to the pointer to the buffer into which the line
 *          should be read; if *s==NULL, a buffer of the necessary size
 *          to hold the data will be allocated from the request pool
 * @param n The size of the buffer
 * @param read The length of the line.
 * @param r The request
 * @param fold Whether to merge continuation lines
 * @param bb Working brigade to use when reading buckets
 * @return APR_SUCCESS, if successful
 *         APR_ENOSPC, if the line is too big to fit in the buffer
 *         Other errors where appropriate
 */
#if APR_CHARSET_EBCDIC
AP_DECLARE(apr_status_t) ap_rgetline(char **s, apr_size_t n, 
                                     apr_size_t *read,
                                     request_rec *r, int fold,
                                     apr_bucket_brigade *bb);
#else /* ASCII box */
#define ap_rgetline(s, n, read, r, fold, bb) \
        ap_rgetline_core((s), (n), (read), (r), (fold), (bb))
#endif
AP_DECLARE(apr_status_t) ap_rgetline_core(char **s, apr_size_t n, 
                                          apr_size_t *read,
                                          request_rec *r, int fold,
                                          apr_bucket_brigade *bb);

/**
 * Get the method number associated with the given string, assumed to
 * contain an HTTP method.  Returns M_INVALID if not recognized.
 * @param method A string containing a valid HTTP method
 * @return The method number
 */
AP_DECLARE(int) ap_method_number_of(const char *method);

/**
 * Get the method name associated with the given internal method
 * number.  Returns NULL if not recognized.
 * @param p A pool to use for temporary allocations.
 * @param methnum An integer value corresponding to an internal method number
 * @return The name corresponding to the method number
 */
AP_DECLARE(const char *) ap_method_name_of(apr_pool_t *p, int methnum);


  /* Hooks */
  /*
   * post_read_request --- run right after read_request or internal_redirect,
   *                  and not run during any subrequests.
   */
/**
 * This hook allows modules to affect the request immediately after the request
 * has been read, and before any other phases have been processes.  This allows
 * modules to make decisions based upon the input header fields
 * @param r The current request
 * @return OK or DECLINED
 * @deffunc ap_run_post_read_request(request_rec *r)
 */
AP_DECLARE_HOOK(int,post_read_request,(request_rec *r))

/**
 * This hook allows modules to perform any module-specific logging activities
 * over and above the normal server things.
 * @param r The current request
 * @return OK, DECLINED, or HTTP_...
 * @deffunc int ap_run_log_transaction(request_rec *r)
 */
AP_DECLARE_HOOK(int,log_transaction,(request_rec *r))

/**
 * This hook allows modules to retrieve the http method from a request.  This
 * allows Apache modules to easily extend the methods that Apache understands
 * @param r The current request
 * @return The http method from the request
 * @deffunc const char *ap_run_http_method(const request_rec *r)
 */
AP_DECLARE_HOOK(const char *,http_method,(const request_rec *r))

/**
 * Return the default port from the current request
 * @param r The current request
 * @return The current port
 * @deffunc apr_port_t ap_run_default_port(const request_rec *r)
 */
AP_DECLARE_HOOK(apr_port_t,default_port,(const request_rec *r))

typedef struct ap_bucket_error ap_bucket_error;

/**
 * A bucket referring to an HTTP error
 * This bucket can be passed down the filter stack to indicate that an
 * HTTP error occurred while running a filter.  In order for this bucket
 * to be used successfully, it MUST be sent as the first bucket in the
 * first brigade to be sent from a given filter.
 */
struct ap_bucket_error {
    /** Number of buckets using this memory */
    apr_bucket_refcount refcount;
    /** The error code */
    int status;
    /** The error string */
    const char    *data;
};

AP_DECLARE_DATA extern const apr_bucket_type_t ap_bucket_type_error;

/**
 * Determine if a bucket is an error bucket
 * @param e The bucket to inspect
 * @return true or false
 */
#define AP_BUCKET_IS_ERROR(e)         (e->type == &ap_bucket_type_error)

/**
 * Make the bucket passed in an error bucket
 * @param b The bucket to make into an error bucket
 * @param error The HTTP error code to put in the bucket. 
 * @param buf An optional error string to put in the bucket.
 * @param p A pool to allocate out of.
 * @return The new bucket, or NULL if allocation failed
 * @deffunc apr_bucket *ap_bucket_error_make(apr_bucket *b, int error, const char *buf, apr_pool_t *p)
 */
AP_DECLARE(apr_bucket *) ap_bucket_error_make(apr_bucket *b, int error,
                const char *buf, apr_pool_t *p);

/**
 * Create a bucket referring to an HTTP error.
 * @param error The HTTP error code to put in the bucket. 
 * @param buf An optional error string to put in the bucket.
 * @param p A pool to allocate the error string out of.
 * @param list The bucket allocator from which to allocate the bucket
 * @return The new bucket, or NULL if allocation failed
 * @deffunc apr_bucket *ap_bucket_error_create(int error, const char *buf, apr_pool_t *p, apr_bucket_alloc_t *list)
 */
AP_DECLARE(apr_bucket *) ap_bucket_error_create(int error, const char *buf,
                                                apr_pool_t *p,
                                                apr_bucket_alloc_t *list);

AP_DECLARE_NONSTD(apr_status_t) ap_byterange_filter(ap_filter_t *f, apr_bucket_brigade *b);
AP_DECLARE_NONSTD(apr_status_t) ap_http_header_filter(ap_filter_t *f, apr_bucket_brigade *b);
AP_DECLARE_NONSTD(apr_status_t) ap_content_length_filter(ap_filter_t *,
                                                              apr_bucket_brigade *);
AP_DECLARE_NONSTD(apr_status_t) ap_old_write_filter(ap_filter_t *f, apr_bucket_brigade *b);

/*
 * Setting up the protocol fields for subsidiary requests...
 * Also, a wrapup function to keep the internal accounting straight.
 */
AP_DECLARE(void) ap_set_sub_req_protocol(request_rec *rnew, const request_rec *r);
AP_DECLARE(void) ap_finalize_sub_req_protocol(request_rec *sub_r);
                                                                                
#ifdef __cplusplus
}
#endif

#endif	/* !APACHE_HTTP_PROTOCOL_H */