c16a9fa493
It works and can format all "plain" Perl data, but has a few known bugs and limitations that still need to be worked out. It's about 8x smaller than JSON::XS's encoder and *much* smaller than Cpanel::JSON::XS, but this is just a first attempt, it'll grow.
43 lines
1.2 KiB
C
43 lines
1.2 KiB
C
/* Custom string builder, comparable to functionality provided by SV*
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* functions, but with less magic and better inlineable. */
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typedef struct {
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size_t len;
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size_t size;
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char *buf;
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} fustr;
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/* No need to call this, an empty fustr is already usable.
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* This allows setting a custom initial size. */
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static void fustr_init(fustr *s, size_t prealloc) {
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s->len = 0;
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s->size = prealloc;
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s->buf = safemalloc(prealloc);
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}
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static void fustr_grow(fustr *s, size_t add) {
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if (s->size == 0) s->size = 512;
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while (s->size < s->len + add)
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s->size *= 2;
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s->buf = saferealloc(s->buf, s->size);
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}
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#define fustr_reserve(s, n) do {\
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if (UNLIKELY((s)->size < (s)->len + (n))) fustr_grow(s, n);\
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} while(0)
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#define fustr_write(s, str, n) do {\
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fustr_reserve(s, n);\
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memcpy((s)->buf+(s)->len, str, (n));\
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(s)->len += (n);\
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} while(0)
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/* Move the string buffer into a new SV; fustr should be considered invalid after this call.
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* Does not set the UTF8 flag. */
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static SV *fustr_sv(fustr *s) {
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SV *r = newSV(0);
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fustr_write(s, "", 1); // trailing nul
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sv_usepvn_flags(r, s->buf, s->len-1, SV_HAS_TRAILING_NUL);
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// TODO: SvPV_shrink_to_cur?
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return r;
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}
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