util.h

/*
 * restgres_evutil.h
 *
 *  Created on: Sep 14, 2014
 *      Author: dobes
 */

#ifndef RESTGRES_UTIL_H_
#define RESTGRES_UTIL_H_

#include <event2/util.h>
#include <event2/http.h>
#include <event2/buffer.h>

const char *
remove_prefix(const char *name, const char *path);

/* Add a cstring to a buffer */
void
evbuffer_add_cstring(struct evbuffer *buf, const char *str);

/* Add a single character to a buffer */
void
evbuffer_add_char(struct evbuffer *buf, char ch);

/* Add CRLF to a buffer */
void
evbuffer_add_crlf(struct evbuffer *buf);

/* Quote and escape the given cstring and append it to the buffer */
void
evbuffer_add_json_cstring(struct evbuffer *buf, const char *str);

/* Quote and escape the given cstring key/value pair and append them to the buffer separated by ':' */
void
evbuffer_add_json_cstring_pair(struct evbuffer *buf, const char *key, const char *value);

/*
 * Escape quotes in the string, if there are any.  If not, returns the original string.  Any
 * new string returned is allocated using palloc, which means it will be freed at the end of the request
 * processing.
 */
const char *
_escape_quotes(const char *input, char q);

/* Escape double quotes; see _escape_quotes */
const char *
_escape_double_quotes(const char *input);

/**
 * Get a evhttp_cmd_type for a char *
 */
enum evhttp_cmd_type
method_cmd_type(const char *method);

/**
 * Get a char * for a evhttp_cmd_type.
 */
const char *
cmd_type_method(enum evhttp_cmd_type cmd_type);

/*
 * Append a buffer to a buffer as a netstring.
 *
 * If drain_src is true the source buffer is drained and some copying might
 * be avoided.
 */
void
evbuffer_add_netstring_buffer(struct evbuffer *buf, struct evbuffer *string, bool drain_src);

/*
 * Append a C string to an evbuffer as a netstring
 */
void
evbuffer_add_netstring_cstring(struct evbuffer *buf, const char *string);

/* Add a formatted string as a netstring */
int
evbuffer_add_netstring_vprintf(struct evbuffer *buf, const char *fmt, va_list ap)
#ifdef __GNUC__
	__attribute__((format(printf, 2, 0)))
#endif
;

/* Add a formatted string as a netstring */
int
evbuffer_add_netstring_printf(struct evbuffer *buf, const char *fmt, ...)
#ifdef __GNUC__
	__attribute__((format(printf, 2, 0)))
#endif
;


/* Add headers to the given output buffer, separated using CRLF */
void
evbuffer_add_headers(struct evbuffer *reply_buffer, struct evkeyvalq *headers);

/*
 * Read a netstring from the input.  The input must contain a complete
 * netstring.
 *
 * If the input doesn't contain a whole netstring, this returns the number
 * of additional bytes needed if the length of the netstring was available,
 * or -1 if the length of the netstring was not availabe.
 *
 * If the netstring is fully available, this copies it into the provided buffer
 * and returns 0.
 */
ssize_t
evbuffer_remove_netstring_buffer(struct evbuffer *input, struct evbuffer *output);

/**
 * Wait until a whole netstring is available on fd, using input as the buffer,
 * then move that netstring into output.
 *
 * This assumes the fd will block on read() when there's no input.
 *
 * Extra bytes read in the process will be left in the input buffer; also, any
 * bytes already in the input buffer may be consumed to read the netstring.
 *
 * If read() returns -1, this will return -1, otherwise this returns 0.
 */
int
read_netstring_buffer(pgsocket fd, struct evbuffer *input, struct evbuffer *output, int read_size);

/**
 * Wait until a whole netstring is available on fd, using input as the buffer,
 * then move that netstring into a char buffer allocated using palloc() and
 * return it.
 *
 * This assumes the fd will block on read()  when there's no input.
 *
 * Extra bytes read in the process will be left in the input buffer; also, any
 * bytes already in the input buffer may be consumed to read the netstring.
 *
 * If read() returns -1, this will return NULL.
 */
char *
read_netstring_cstring(pgsocket fd, struct evbuffer *input, int read_size);

/*
 * Read a netstring from the input.  The input must contain a complete
 * netstring.  Returns a newly allocated cstring, which the caller must
 * free using free().  If the input doesn't contain the whole
 * netstring, return NULL.
 */
char *
evbuffer_remove_netstring_cstring(struct evbuffer *input);

/* Parse pairs of netstrings into an evhttp headers data structure */
int
evbuffer_parse_scgi_headers(struct evbuffer *input, struct evkeyvalq *headers);

/*
 * Create a socket and optionally set some flags on it
 */
evutil_socket_t
socket_with_flags(int domain, int type, int protocol);

/*
 * Create a socket and bind() it to the given address
 */
evutil_socket_t
bound_socket(struct evutil_addrinfo *ai, int reuse);

/*
 * Check whether the input starts with the given path component; returns the remainder of the string if so
 * Return NULL if the prefix doesn't match.
 */
const char *
remove_prefix(const char *prefix, const char *input);

/*
 * NULL-safe string equality check.  If both strings are NULL, returns true.  If only
 * one is NULL, returns false.  If both are not NULL, streql returns strcmp(a,b) == 0.
 */
bool
streql(const char *a, const char *b);

/*
 * Get the uid, gid, and pid of the connected peer.
 *
 * All the out parameters must be non-NULL.
 *
 * Returns -1 on failure or 0 on success; errno should be set on failure.
 */
int
getpeerpideid(int sock, pid_t *pid, uid_t *uid, gid_t *gid);

/* Add Content-Type: application/json;charset=utf8 to headers */
void
add_json_content_type_header(struct evkeyvalq *headers);

/*
 * Appends a path component to an existing path.  The "ext" is URL escaped and the result
 * is joined to the "base" with a "/" in between.  The result is allocated using palloc().
 *
 */
char *
pstr_uri_append_path_component(const char *base, const char *ext);

struct jsonbuf;

/*
 * Add a link json object for a role
 */
void
jsonbuf_element_role_link(struct jsonbuf *jp, const char *key, Oid roleOid);

/*
 * Add a link json object for a tablespace
 */
void
jsonbuf_add_tablespace_link(struct jsonbuf* jp, const char *key, Oid tablespaceOid);

#endif /* RESTGRES_EVUTIL_H_ */