ceph/src/seastar/dpdk/lib/librte_kvargs/rte_kvargs.h

   1 /* SPDX-License-Identifier: BSD-3-Clause
   2  * Copyright(c) 2010-2013 Intel Corporation.
   3  * Copyright(c) 2014 6WIND S.A.
   4  */
   5
   6 #ifndef _RTE_KVARGS_H_
   7 #define _RTE_KVARGS_H_
   8
   9 /**
  10  * @file
  11  * RTE Argument parsing
  12  *
  13  * This module can be used to parse arguments whose format is
  14  * key1=value1,key2=value2,key3=value3,...
  15  *
  16  * The same key can appear several times with the same or a different
  17  * value. Indeed, the arguments are stored as a list of key/values
  18  * associations and not as a dictionary.
  19  *
  20  * This file provides some helpers that are especially used by virtual
  21  * ethernet devices at initialization for arguments parsing.
  22  */
  23
  24 #ifdef __cplusplus
  25 extern "C" {
  26 #endif
  27
  28 #include <rte_compat.h>
  29
  30 /** Maximum number of key/value associations */
  31 #define RTE_KVARGS_MAX 32
  32
  33 /** separator character used between each pair */
  34 #define RTE_KVARGS_PAIRS_DELIM  ","
  35
  36 /** separator character used between key and value */
  37 #define RTE_KVARGS_KV_DELIM     "="
  38
  39 /** Type of callback function used by rte_kvargs_process() */
  40 typedef int (*arg_handler_t)(const char *key, const char *value, void *opaque);
  41
  42 /** A key/value association */
  43 struct rte_kvargs_pair {
  44         char *key;      /**< the name (key) of the association  */
  45         char *value;    /**< the value associated to that key */
  46 };
  47
  48 /** Store a list of key/value associations */
  49 struct rte_kvargs {
  50         char *str;      /**< copy of the argument string */
  51         unsigned count; /**< number of entries in the list */
  52         struct rte_kvargs_pair pairs[RTE_KVARGS_MAX]; /**< list of key/values */
  53 };
  54
  55 /**
  56  * Allocate a rte_kvargs and store key/value associations from a string
  57  *
  58  * The function allocates and fills a rte_kvargs structure from a given
  59  * string whose format is key1=value1,key2=value2,...
  60  *
  61  * The structure can be freed with rte_kvargs_free().
  62  *
  63  * @param args
  64  *   The input string containing the key/value associations
  65  * @param valid_keys
  66  *   A list of valid keys (table of const char *, the last must be NULL).
  67  *   This argument is ignored if NULL
  68  *
  69  * @return
  70  *   - A pointer to an allocated rte_kvargs structure on success
  71  *   - NULL on error
  72  */
  73 struct rte_kvargs *rte_kvargs_parse(const char *args,
  74                 const char *const valid_keys[]);
  75
  76 /**
  77  * Allocate a rte_kvargs and store key/value associations from a string.
  78  * This version will consider any byte from valid_ends as a possible
  79  * terminating character, and will not parse beyond any of their occurrence.
  80  *
  81  * The function allocates and fills an rte_kvargs structure from a given
  82  * string whose format is key1=value1,key2=value2,...
  83  *
  84  * The structure can be freed with rte_kvargs_free().
  85  *
  86  * @param args
  87  *   The input string containing the key/value associations
  88  *
  89  * @param valid_keys
  90  *   A list of valid keys (table of const char *, the last must be NULL).
  91  *   This argument is ignored if NULL
  92  *
  93  * @param valid_ends
  94  *   Acceptable terminating characters.
  95  *   If NULL, the behavior is the same as ``rte_kvargs_parse``.
  96  *
  97  * @return
  98  *   - A pointer to an allocated rte_kvargs structure on success
  99  *   - NULL on error
 100  */
 101 __rte_experimental
 102 struct rte_kvargs *rte_kvargs_parse_delim(const char *args,
 103                 const char *const valid_keys[],
 104                 const char *valid_ends);
 105
 106 /**
 107  * Free a rte_kvargs structure
 108  *
 109  * Free a rte_kvargs structure previously allocated with
 110  * rte_kvargs_parse().
 111  *
 112  * @param kvlist
 113  *   The rte_kvargs structure. No error if NULL.
 114  */
 115 void rte_kvargs_free(struct rte_kvargs *kvlist);
 116
 117 /**
 118  * Call a handler function for each key/value matching the key
 119  *
 120  * For each key/value association that matches the given key, calls the
 121  * handler function with the for a given arg_name passing the value on the
 122  * dictionary for that key and a given extra argument.
 123  *
 124  * @param kvlist
 125  *   The rte_kvargs structure. No error if NULL.
 126  * @param key_match
 127  *   The key on which the handler should be called, or NULL to process handler
 128  *   on all associations
 129  * @param handler
 130  *   The function to call for each matching key
 131  * @param opaque_arg
 132  *   A pointer passed unchanged to the handler
 133  *
 134  * @return
 135  *   - 0 on success
 136  *   - Negative on error
 137  */
 138 int rte_kvargs_process(const struct rte_kvargs *kvlist,
 139         const char *key_match, arg_handler_t handler, void *opaque_arg);
 140
 141 /**
 142  * Count the number of associations matching the given key
 143  *
 144  * @param kvlist
 145  *   The rte_kvargs structure
 146  * @param key_match
 147  *   The key that should match, or NULL to count all associations
 148
 149  * @return
 150  *   The number of entries
 151  */
 152 unsigned rte_kvargs_count(const struct rte_kvargs *kvlist,
 153         const char *key_match);
 154
 155 /**
 156  * Generic kvarg handler for string comparison.
 157  *
 158  * This function can be used for a generic string comparison processing
 159  * on a list of kvargs.
 160  *
 161  * @param key
 162  *   kvarg pair key.
 163  *
 164  * @param value
 165  *   kvarg pair value.
 166  *
 167  * @param opaque
 168  *   Opaque pointer to a string.
 169  *
 170  * @return
 171  *   0 if the strings match.
 172  *   !0 otherwise or on error.
 173  *
 174  *   Unless strcmp, comparison ordering is not kept.
 175  *   In order for rte_kvargs_process to stop processing on match error,
 176  *   a negative value is returned even if strcmp had returned a positive one.
 177  */
 178 __rte_experimental
 179 int rte_kvargs_strcmp(const char *key, const char *value, void *opaque);
 180
 181 #ifdef __cplusplus
 182 }
 183 #endif
 184
 185 #endif