xref: /freebsd/contrib/libxo/libxo/xo_encoder.h (revision 773bec086828bf0f1ba663958853823f7a059fb5)
1 /*
2  * Copyright (c) 2015, Juniper Networks, Inc.
3  * All rights reserved.
4  * This SOFTWARE is licensed under the LICENSE provided in the
5  * ../Copyright file. By downloading, installing, copying, or otherwise
6  * using the SOFTWARE, you agree to be bound by the terms of that
7  * LICENSE.
8  * Phil Shafer, August 2015
9  */
10 
11 /*
12  * NOTE WELL: This file is needed to software that implements an
13  * external encoder for libxo that allows libxo data to be encoded in
14  * new and bizarre formats.  General libxo code should _never_
15  * include this header file.
16  */
17 
18 #ifndef XO_ENCODER_H
19 #define XO_ENCODER_H
20 
21 #include <string.h>
22 
23 /*
24  * Expose libxo's memory allocation functions
25  */
26 extern xo_realloc_func_t xo_realloc;
27 extern xo_free_func_t xo_free;
28 
29 /*
30  * Simple string comparison function (without the temptation
31  * to forget the "== 0").
32  */
33 static inline int
xo_streq(const char * one,const char * two)34 xo_streq (const char *one, const char *two)
35 {
36     return strcmp(one, two) == 0;
37 }
38 
39 /* Flags for formatting functions */
40 typedef unsigned long xo_xff_flags_t;
41 #define XFF_COLON	(1<<0)	/* Append a ":" */
42 #define XFF_COMMA	(1<<1)	/* Append a "," iff there's more output */
43 #define XFF_WS		(1<<2)	/* Append a blank */
44 #define XFF_ENCODE_ONLY	(1<<3)	/* Only emit for encoding styles (XML, JSON) */
45 
46 #define XFF_QUOTE	(1<<4)	/* Force quotes */
47 #define XFF_NOQUOTE	(1<<5)	/* Force no quotes */
48 #define XFF_DISPLAY_ONLY (1<<6)	/* Only emit for display styles (text, html) */
49 #define XFF_KEY		(1<<7)	/* Field is a key (for XPath) */
50 
51 #define XFF_XML		(1<<8)	/* Force XML encoding style (for XPath) */
52 #define XFF_ATTR	(1<<9)	/* Escape value using attribute rules (XML) */
53 #define XFF_BLANK_LINE	(1<<10)	/* Emit a blank line */
54 #define XFF_NO_OUTPUT	(1<<11)	/* Do not make any output */
55 
56 #define XFF_TRIM_WS	(1<<12)	/* Trim whitespace off encoded values */
57 #define XFF_LEAF_LIST	(1<<13)	/* A leaf-list (list of values) */
58 #define XFF_UNESCAPE	(1<<14)	/* Need to printf-style unescape the value */
59 #define XFF_HUMANIZE	(1<<15)	/* Humanize the value (for display styles) */
60 
61 #define XFF_HN_SPACE	(1<<16)	/* Humanize: put space before suffix */
62 #define XFF_HN_DECIMAL	(1<<17)	/* Humanize: add one decimal place if <10 */
63 #define XFF_HN_1000	(1<<18)	/* Humanize: use 1000, not 1024 */
64 #define XFF_GT_FIELD	(1<<19) /* Call gettext() on a field */
65 
66 #define XFF_GT_PLURAL	(1<<20)	/* Call dngettext to find plural form */
67 #define XFF_ARGUMENT	(1<<21)	/* Content provided via argument */
68 
69 /* Flags to turn off when we don't want i18n processing */
70 #define XFF_GT_FLAGS (XFF_GT_FIELD | XFF_GT_PLURAL)
71 
72 typedef unsigned xo_encoder_op_t;
73 
74 /* Encoder operations; names are in xo_encoder.c:xo_encoder_op_name() */
75 #define XO_OP_UNKNOWN		0
76 #define XO_OP_CREATE		1 /* Called when the handle is init'd */
77 #define XO_OP_OPEN_CONTAINER	2
78 #define XO_OP_CLOSE_CONTAINER	3
79 #define XO_OP_OPEN_LIST		4
80 #define XO_OP_CLOSE_LIST	5
81 #define XO_OP_OPEN_LEAF_LIST	6
82 #define XO_OP_CLOSE_LEAF_LIST	7
83 #define XO_OP_OPEN_INSTANCE	8
84 #define XO_OP_CLOSE_INSTANCE	9
85 #define XO_OP_STRING		10 /* Quoted UTF-8 string */
86 #define XO_OP_CONTENT		11 /* Other content */
87 #define XO_OP_FINISH		12 /* Finish any pending output */
88 #define XO_OP_FLUSH		13 /* Flush any buffered output */
89 #define XO_OP_DESTROY		14 /* Clean up function */
90 #define XO_OP_ATTRIBUTE		15 /* Attribute name/value */
91 #define XO_OP_VERSION		16 /* Version string */
92 #define XO_OP_OPTIONS		17 /* Additional command line options */
93 #define XO_OP_OPTIONS_PLUS	18 /* Additional command line options */
94 
95 #define XO_ENCODER_HANDLER_ARGS					\
96 	xo_handle_t *xop __attribute__ ((__unused__)),		\
97 	xo_encoder_op_t op __attribute__ ((__unused__)),	\
98 	const char *name __attribute__ ((__unused__)),		\
99         const char *value __attribute__ ((__unused__)),		\
100 	void *private __attribute__ ((__unused__)),		\
101 	xo_xff_flags_t flags __attribute__ ((__unused__))
102 
103 typedef int (*xo_encoder_func_t)(XO_ENCODER_HANDLER_ARGS);
104 
105 typedef struct xo_encoder_init_args_s {
106     unsigned xei_version;	   /* Current version */
107     xo_encoder_func_t xei_handler; /* Encoding handler */
108 } xo_encoder_init_args_t;
109 
110 #define XO_ENCODER_VERSION	1 /* Current version */
111 
112 #define XO_ENCODER_INIT_ARGS \
113     xo_encoder_init_args_t *arg __attribute__ ((__unused__))
114 
115 typedef int (*xo_encoder_init_func_t)(XO_ENCODER_INIT_ARGS);
116 /*
117  * Each encoder library must define a function named xo_encoder_init
118  * that takes the arguments defined in XO_ENCODER_INIT_ARGS.  It
119  * should return zero for success.
120  */
121 #define XO_ENCODER_INIT_NAME_TOKEN xo_encoder_library_init
122 #define XO_STRINGIFY(_x) #_x
123 #define XO_STRINGIFY2(_x) XO_STRINGIFY(_x)
124 #define XO_ENCODER_INIT_NAME XO_STRINGIFY2(XO_ENCODER_INIT_NAME_TOKEN)
125 extern int XO_ENCODER_INIT_NAME_TOKEN (XO_ENCODER_INIT_ARGS);
126 
127 void
128 xo_encoder_register (const char *name, xo_encoder_func_t func);
129 
130 void
131 xo_encoder_unregister (const char *name);
132 
133 void *
134 xo_get_private (xo_handle_t *xop);
135 
136 void
137 xo_encoder_path_add (const char *path);
138 
139 void
140 xo_set_private (xo_handle_t *xop, void *opaque);
141 
142 xo_encoder_func_t
143 xo_get_encoder (xo_handle_t *xop);
144 
145 void
146 xo_set_encoder (xo_handle_t *xop, xo_encoder_func_t encoder);
147 
148 int
149 xo_encoder_init (xo_handle_t *xop, const char *name);
150 
151 xo_handle_t *
152 xo_encoder_create (const char *name, xo_xof_flags_t flags);
153 
154 int
155 xo_encoder_handle (xo_handle_t *xop, xo_encoder_op_t op,
156 		   const char *name, const char *value, xo_xff_flags_t flags);
157 
158 void
159 xo_encoders_clean (void);
160 
161 const char *
162 xo_encoder_op_name (xo_encoder_op_t op);
163 
164 /*
165  * xo_failure is used to announce internal failures, when "warn" is on
166  */
167 void
168 xo_failure (xo_handle_t *xop, const char *fmt, ...);
169 
170 #endif /* XO_ENCODER_H */
171