lsxpack_header.h revision a5fa05f9 
1/* Copyright (c) 2017 - 2020 LiteSpeed Technologies Inc.  See LICENSE. */
2#ifndef LSXPACK_HEADER_H_v203
3#define LSXPACK_HEADER_H_v203
4
5#ifdef __cplusplus
6extern "C" {
7#endif
8
9#include <assert.h>
10#include <stdint.h>
11#include <string.h>
12
13#ifndef LSXPACK_MAX_STRLEN
14#define LSXPACK_MAX_STRLEN UINT16_MAX
15#endif
16
17#if LSXPACK_MAX_STRLEN == UINT16_MAX
18typedef uint16_t lsxpack_strlen_t;
19#elif LSXPACK_MAX_STRLEN == UINT32_MAX
20typedef uint32_t lsxpack_strlen_t;
21#else
22#error unexpected LSXPACK_MAX_STRLEN
23#endif
24
25enum lsxpack_flag
26{
27    LSXPACK_HPACK_IDX = 1,
28    LSXPACK_QPACK_IDX = 2,
29    LSXPACK_APP_IDX   = 4,
30    LSXPACK_NAME_HASH = 8,
31    LSXPACK_NAMEVAL_HASH = 16,
32    LSXPACK_VAL_MATCHED = 32,
33    LSXPACK_NEVER_INDEX = 64,
34};
35
36/**
37 * When header are decoded, it should be stored to @buf starting from @name_offset,
38 *    <name>: <value>\r\n
39 * So, it can be used directly as HTTP/1.1 header. there are 4 extra characters
40 * added.
41 *
42 * limitation: we currently does not support total header size > 64KB.
43 */
44
45struct lsxpack_header
46{
47    char             *buf;          /* the buffer for headers */
48    const char       *name_ptr;     /* the name pointer can be optionally set for encoding */
49    uint32_t          name_hash;    /* hash value for name */
50    uint32_t          nameval_hash; /* hash value for name + value */
51    lsxpack_strlen_t  name_offset;  /* the offset for name in the buffer */
52    lsxpack_strlen_t  name_len;     /* the length of name */
53    lsxpack_strlen_t  val_offset;   /* the offset for value in the buffer */
54    lsxpack_strlen_t  val_len;      /* the length of value */
55    uint8_t           hpack_index;  /* HPACK static table index */
56    uint8_t           qpack_index;  /* QPACK static table index */
57    uint8_t           app_index;    /* APP header index */
58    enum lsxpack_flag flags:8;      /* combination of lsxpack_flag */
59    uint8_t           indexed_type; /* control to disable index or not */
60    uint8_t           dec_overhead; /* num of extra bytes written to decoded buffer */
61};
62
63typedef struct lsxpack_header lsxpack_header_t;
64
65
66static inline void
67lsxpack_header_set_idx(lsxpack_header_t *hdr, int hpack_idx,
68                       const char *val, size_t val_len)
69{
70    memset(hdr, 0, sizeof(*hdr));
71    hdr->buf = (char *)val;
72    hdr->hpack_index = hpack_idx;
73    assert(hpack_idx != 0);
74    hdr->flags = LSXPACK_HPACK_IDX;
75    assert(val_len <= LSXPACK_MAX_STRLEN);
76    hdr->val_len = val_len;
77}
78
79
80static inline void
81lsxpack_header_set_ptr(lsxpack_header_t *hdr,
82                       const char *name, size_t name_len,
83                       const char *val, size_t val_len)
84{
85    memset(hdr, 0, sizeof(*hdr));
86    hdr->buf = (char *)val;
87    assert(val_len <= LSXPACK_MAX_STRLEN);
88    hdr->val_len = val_len;
89    hdr->name_ptr = name;
90    assert(name_len <= LSXPACK_MAX_STRLEN);
91    hdr->name_len = name_len;
92}
93
94
95static inline void
96lsxpack_header_set_offset(lsxpack_header_t *hdr, const char *buf,
97                          size_t name_offset, size_t name_len,
98                          size_t val_len)
99{
100    memset(hdr, 0, sizeof(*hdr));
101    hdr->buf = (char *)buf;
102    hdr->name_offset = name_offset;
103    assert(name_len <= LSXPACK_MAX_STRLEN);
104    hdr->name_len = name_len;
105    assert(name_offset + name_len + 2 <= LSXPACK_MAX_STRLEN);
106    hdr->val_offset = name_offset + name_len + 2;
107    assert(val_len <= LSXPACK_MAX_STRLEN);
108    hdr->val_len = val_len;
109}
110
111
112static inline void
113lsxpack_header_set_offset2(lsxpack_header_t *hdr, const char *buf,
114                           size_t name_offset, size_t name_len,
115                           size_t val_offset, size_t val_len)
116{
117    memset(hdr, 0, sizeof(*hdr));
118    hdr->buf = (char *)buf;
119    hdr->name_offset = name_offset;
120    assert(name_len <= LSXPACK_MAX_STRLEN);
121    hdr->name_len = name_len;
122    assert(val_offset <= LSXPACK_MAX_STRLEN);
123    hdr->val_offset = val_offset;
124    assert(val_len <= LSXPACK_MAX_STRLEN);
125    hdr->val_len = val_len;
126}
127
128
129static inline void
130lsxpack_header_prepare_decode(lsxpack_header_t *hdr,
131                              char *out, size_t offset, size_t len)
132{
133    memset(hdr, 0, sizeof(*hdr));
134    hdr->buf = out;
135    assert(offset <= LSXPACK_MAX_STRLEN);
136    hdr->name_offset = offset;
137    if (len > LSXPACK_MAX_STRLEN)
138        hdr->val_len = LSXPACK_MAX_STRLEN;
139    else
140        hdr->val_len = len;
141}
142
143
144static inline const char *
145lsxpack_header_get_name(const lsxpack_header_t *hdr)
146{
147    return hdr->name_ptr ? hdr->name_ptr
148                         : (hdr->name_len) ? hdr->buf + hdr->name_offset
149                                           : NULL;
150}
151
152
153static inline const char *
154lsxpack_header_get_value(const lsxpack_header_t *hdr)
155{   return hdr->buf + hdr->val_offset;  }
156
157static inline size_t
158lsxpack_header_get_dec_size(const lsxpack_header_t *hdr)
159{   return hdr->name_len + hdr->val_len + hdr->dec_overhead;    }
160
161#ifdef __cplusplus
162}
163#endif
164
165#endif //LSXPACK_HEADER_H_v203
166