`nx_url_params.nx` source

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1// nx_url_params.nx -- bits-up URL query-string parser for the Nishi
2// test harness arc.  Mirrors what nishi-host.js does today in JS:
3// extracting `?v=N` from a URL string for sovereign version pinning.
4//
5// Scope: only what the test driver needs.  No URL-encoding, no
6// fragment handling, no multi-value params (those are queued via
7// the full nishi-browser arc).
8
9import "nx_syscalls.nx"
10
11struct NxUrlParam {
12    found: i64,         // 1 if param present
13    val_off: i64,       // offset of value within URL string
14    val_len: i64        // byte length of value
15}
16
17func _up_strlen(s: *u8) -> i64 {
18    var n: i64 = 0
19    while s[n] != 0 { n = n + 1 }
20    return n
21}
22
23func _up_byte_eq(a: *u8, ao: i64, b: *u8, bo: i64, n: i64) -> i64 {
24    var i: i64 = 0
25    while i < n {
26        if a[ao + i] != b[bo + i] { return 0 }
27        i = i + 1
28    }
29    return 1
30}
31
32// Scan a key-delimiter (one of '=' '&' '#') or end.  Returns position
33// of the delimiter, or url_len if none.
34func _up_scan_key_end(url: *u8, url_len: i64, start: i64) -> i64 {
35    var p: i64 = start
36    while p < url_len {
37        let b: i64 = url[p] as i64
38        if b == 61 { return p }
39        if b == 38 { return p }
40        if b == 35 { return p }
41        p = p + 1
42    }
43    return p
44}
45
46// Scan a value-delimiter (one of '&' '#') or end.
47func _up_scan_val_end(url: *u8, url_len: i64, start: i64) -> i64 {
48    var p: i64 = start
49    while p < url_len {
50        let b: i64 = url[p] as i64
51        if b == 38 { return p }
52        if b == 35 { return p }
53        p = p + 1
54    }
55    return p
56}
57
58// Find the start of the query string ('?').  Returns offset just past
59// the '?' or -1 if none.
60func nx_url_query_start(url: *u8, url_len: i64) -> i64 {
61    var i: i64 = 0
62    while i < url_len {
63        if url[i] == 63 { return i + 1 }    // '?'
64        if url[i] == 35 { return -1 }       // '#' before '?' -> no query
65        i = i + 1
66    }
67    return -1
68}
69
70// Parse a single named param from the URL.  Single-exit pattern --
71// accumulate into out_found / out_val_off / out_val_len cells, then
72// pack into the result struct at function-end.  NishiLang's scope
73// tracker loses an outer-scope struct pointer when an early-return
74// appears inside a nested-then-closed `if` block, so we sidestep it.
75func nx_url_param_get(url: *u8, url_len: i64, name: *u8) -> *NxUrlParam {
76    let out_found:   *i64 = sys_mmap(8) as *i64
77    let out_val_off: *i64 = sys_mmap(8) as *i64
78    let out_val_len: *i64 = sys_mmap(8) as *i64
79    out_found[0]   = 0
80    out_val_off[0] = -1
81    out_val_len[0] = 0
82
83    let qs_start: i64 = nx_url_query_start(url, url_len)
84    let nlen: i64 = _up_strlen(name)
85    var done: i64 = 0
86    if qs_start < 0 { done = 1 }
87    if nlen == 0    { done = 1 }
88
89    var pos: i64 = qs_start
90    while done == 0 {
91        if pos >= url_len { done = 1 }
92        if done == 0 {
93            let kstart: i64 = pos
94            let kend: i64 = _up_scan_key_end(url, url_len, kstart)
95            let klen: i64 = kend - kstart
96            var matched: i64 = 0
97            if klen == nlen {
98                if _up_byte_eq(url, kstart, name, 0, nlen) == 1 { matched = 1 }
99            }
100            var vstart: i64 = kend
101            var vend: i64 = kend
102            if kend < url_len {
103                if url[kend] == 61 {
104                    vstart = kend + 1
105                    vend = _up_scan_val_end(url, url_len, vstart)
106                }
107            }
108            if matched == 1 {
109                out_found[0]   = 1
110                out_val_off[0] = vstart
111                out_val_len[0] = vend - vstart
112                done = 1
113            }
114            if done == 0 {
115                if vend >= url_len { done = 1 }
116                if done == 0 {
117                    if url[vend] == 35 { done = 1 }
118                    if done == 0 { pos = vend + 1 }
119                }
120            }
121        }
122    }
123
124    let r: *NxUrlParam = sys_mmap(24) as *NxUrlParam
125    r.found   = out_found[0]
126    r.val_off = out_val_off[0]
127    r.val_len = out_val_len[0]
128    return r
129}
130
131// Convenience: parse a decimal integer value (positive only).  Returns
132// -1 if param missing or non-numeric.
133func nx_url_param_int(url: *u8, url_len: i64, name: *u8) -> i64 {
134    let p: *NxUrlParam = nx_url_param_get(url, url_len, name)
135    if p.found != 1 { return -1 }
136    if p.val_len <= 0 { return -1 }
137    var acc: i64 = 0
138    var i: i64 = 0
139    while i < p.val_len {
140        let b: i64 = url[p.val_off + i] as i64
141        if b < 48  { return -1 }
142        if b > 57  { return -1 }
143        acc = acc * 10 + (b - 48)
144        i = i + 1
145    }
146    return acc
147}
nx_url_params.nx source

`nx_url_params.nx` source
