From 37d3a1e152707d2da587440c4cea8601b9ef0fd2 Mon Sep 17 00:00:00 2001 From: eunhhu Date: Sun, 27 Sep 2026 13:14:38 +0100 Subject: Lay Pure out as a core with the parts selected around it The app model, the tree store and the HTTP host lived in prototypes/connections among the earlier document runtime, the store was known only by its format's name, and Vega compiled six Pure sources by path. Now, as the README's principle has it: core/ runtime, flow and the app model (module*.c), with what the core asks of storage (state.h, store.h) store/ the tree store (PURETRE3, PUREREC1) serve/ pure-serve: HTTP host, outbound delivery, JSON in place cli/ pure-run, pure-edit-module A top-level make builds libpure.a (app model and store, for hosts to link) and the hosts; make check runs the store's and the app model's tests. The earlier runtime still builds from prototypes/connections against core/ and store/ (check, check-tree and check-core pass). Design 009 records the rule: parts by role behind libraries; git repositories split by coupling, so the store stays here while its contract moves with the core, and Vega stays apart. --- serve/message-json.c | 281 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 281 insertions(+) create mode 100644 serve/message-json.c (limited to 'serve/message-json.c') diff --git a/serve/message-json.c b/serve/message-json.c new file mode 100644 index 0000000..66c812d --- /dev/null +++ b/serve/message-json.c @@ -0,0 +1,281 @@ +#include "message-json.h" +#include "module-text.h" +#include +#include +#include +#include + +static void write_u32(unsigned char *p, uint32_t v) { for (unsigned i = 0; i < 4; ++i) p[i] = (unsigned char)(v >> (8 * i)); } + +static bool decimal(const char *text, uint64_t maximum, uint64_t *value) { + if (!*text) return false; + uint64_t n = 0; + for (; *text; ++text) { + if (*text < '0' || *text > '9') return false; + unsigned digit = (unsigned)(*text - '0'); + if (n > (maximum - digit) / 10) return false; + n = n * 10 + digit; + } + *value = n; + return true; +} + +/* A JSON number's text: -?(0|[1-9][0-9]*)(.[0-9]+)?([eE][+-]?[0-9]+)?, its + * length (0 if there is none). An integer has neither part after it. */ +static size_t json_number(const unsigned char *p, size_t size, bool *integer) { + size_t i = 0; + *integer = true; + if (i < size && p[i] == '-') ++i; + if (i == size || p[i] < '0' || p[i] > '9') return 0; + if (p[i++] != '0') while (i < size && p[i] >= '0' && p[i] <= '9') ++i; + if (i < size && p[i] == '.') { + *integer = false; + if (++i == size || p[i] < '0' || p[i] > '9') return 0; + while (i < size && p[i] >= '0' && p[i] <= '9') ++i; + } + if (i < size && (p[i] == 'e' || p[i] == 'E')) { + *integer = false; + if (++i < size && (p[i] == '+' || p[i] == '-')) ++i; + if (i == size || p[i] < '0' || p[i] > '9') return 0; + while (i < size && p[i] >= '0' && p[i] <= '9') ++i; + } + return i; +} + +/* A fixed field's value from its text (a query value or a JSON number) into + * the prefix: a u32 in range, or a finite number. */ +bool pure_json_fixed(const PureField *field, const unsigned char *text, size_t size, unsigned char *prefix) { + bool integer; + if (!size || json_number(text, size, &integer) != size || size > 40) return false; + char digits[48]; + memcpy(digits, text, size); + digits[size] = 0; + if (field->type == PURE_FIELD_U32) { + uint64_t n; + if (!integer || !decimal(digits, UINT32_MAX, &n)) return false; + write_u32(prefix + field->offset, (uint32_t)n); + return true; + } + double value = strtod(digits, NULL); + if (!isfinite(value)) return false; + memcpy(prefix + field->offset, &value, 8); + return true; +} + +/* A JSON string's contents (after its opening quote) up to the closing one: + * its length, or 0 when it does not close or holds a control byte. */ +static size_t json_string_end(const unsigned char *p, size_t size) { + for (size_t i = 0; i < size; ++i) { + /* Eight bytes at a time while none is a quote, a backslash or a control byte. */ + const uint64_t ones = UINT64_C(0x0101010101010101), highs = UINT64_C(0x8080808080808080); + for (uint64_t w, q, s; size - i >= 8; i += 8) { + memcpy(&w, p + i, 8); + q = w ^ (ones * '"'); + s = w ^ (ones * '\\'); + if (((q - ones) & ~q & highs) | ((s - ones) & ~s & highs) | ((w - ones * 0x20) & ~w & highs)) break; + } + if (i == size) break; + if (p[i] == '"') return i + 1; + if (p[i] < 0x20) return 0; + if (p[i] == '\\' && ++i == size) return 0; + } + return 0; +} + +static int hex_digit(unsigned char c) { + return c >= '0' && c <= '9' ? c - '0' : c >= 'a' && c <= 'f' ? c - 'a' + 10 : c >= 'A' && c <= 'F' ? c - 'A' + 10 : -1; +} + +static bool json_code(const unsigned char *p, size_t left, uint32_t *code) { + if (left < 4) return false; + *code = 0; + for (int i = 0; i < 4; ++i) { + int d = hex_digit(p[i]); + if (d < 0) return false; + *code = *code << 4 | (uint32_t)d; + } + return true; +} + +/* Unescape a JSON string's contents into out (never longer); false for a + * bad escape or a lone surrogate. The result is checked as UTF-8 after. */ +static bool json_unescape(const unsigned char *in, size_t size, unsigned char *out, size_t *written) { + size_t o = 0; + for (size_t i = 0; i < size;) { + unsigned char b = in[i++]; + if (b != '\\') { out[o++] = b; continue; } + if (i == size) return false; + b = in[i++]; + const char *plain = strchr("\"\\/bfnrt", b); + if (b && plain) { out[o++] = (unsigned char)"\"\\/\b\f\n\r\t"[plain - "\"\\/bfnrt"]; continue; } + uint32_t code, low; + if (b != 'u' || !json_code(in + i, size - i, &code)) return false; + i += 4; + if (code >= 0xDC00 && code <= 0xDFFF) return false; + if (code >= 0xD800 && code <= 0xDBFF) { + if (size - i < 6 || in[i] != '\\' || in[i + 1] != 'u' || !json_code(in + i + 2, size - i - 2, &low) || + low < 0xDC00 || low > 0xDFFF) return false; + i += 6; + code = 0x10000 + ((code - 0xD800) << 10) + (low - 0xDC00); + } + if (code < 0x80) out[o++] = (unsigned char)code; + else if (code < 0x800) { out[o++] = (unsigned char)(0xC0 | code >> 6); out[o++] = (unsigned char)(0x80 | (code & 0x3F)); } + else if (code < 0x10000) { + out[o++] = (unsigned char)(0xE0 | code >> 12); + out[o++] = (unsigned char)(0x80 | (code >> 6 & 0x3F)); + out[o++] = (unsigned char)(0x80 | (code & 0x3F)); + } else { + out[o++] = (unsigned char)(0xF0 | code >> 18); + out[o++] = (unsigned char)(0x80 | (code >> 12 & 0x3F)); + out[o++] = (unsigned char)(0x80 | (code >> 6 & 0x3F)); + out[o++] = (unsigned char)(0x80 | (code & 0x3F)); + } + } + *written = o; + return true; +} + +size_t pure_json_space(const unsigned char *p, size_t at, size_t size) { + while (at < size && (p[at] == ' ' || p[at] == '\t' || p[at] == '\n' || p[at] == '\r')) ++at; + return at; +} + +/* Skip any JSON value at json[*at] (at most 64 deep): a member of an + * answer that names no field. */ +static bool skip_value(const unsigned char *json, size_t size, size_t *at, unsigned depth) { + if (*at == size || depth > 64) return false; + unsigned char b = json[*at]; + bool integer; + if (b == '"') { + size_t end = json_string_end(json + *at + 1, size - *at - 1); + if (!end) return false; + *at += 1 + end; + return true; + } + if (b == '{' || b == '[') { + unsigned char close = b == '{' ? '}' : ']'; + *at = pure_json_space(json, *at + 1, size); + for (bool first = true; *at < size && json[*at] != close; first = false) { + if (!first) { + if (json[(*at)++] != ',') return false; + *at = pure_json_space(json, *at, size); + } + if (close == '}') { + size_t key_end = *at < size && json[*at] == '"' ? json_string_end(json + *at + 1, size - *at - 1) : 0; + if (!key_end) return false; + *at = pure_json_space(json, *at + 1 + key_end, size); + if (*at == size || json[(*at)++] != ':') return false; + *at = pure_json_space(json, *at, size); + } + if (!skip_value(json, size, at, depth + 1)) return false; + *at = pure_json_space(json, *at, size); + } + if (*at == size) return false; + ++*at; + return true; + } + static const char *const words[] = {"true", "false", "null"}; + for (size_t w = 0; w < 3; ++w) + if (size - *at >= strlen(words[w]) && !memcmp(json + *at, words[w], strlen(words[w]))) { + *at += strlen(words[w]); + return true; + } + size_t length = json_number(json + *at, size - *at, &integer); + *at += length; + return length > 0; +} + +/* The field named path.key (key alone at the top), or the field count when + * none is; group says whether fields are named inside it instead. */ +static uint32_t field_named(const PureJsonMessage *b, const char *path, size_t path_size, const unsigned char *key, + size_t key_size, bool *group) { + const PureModule *m = b->module; + size_t size = path_size + !!path_size + key_size; + *group = false; + for (uint32_t f = 0; f < b->shape->field_count; ++f) { + const char *name = m->field[b->shape->field_start + f].name; + size_t length = strlen(name); + if (length < size || memcmp(name, path, path_size) || (path_size && name[path_size] != '.') || + memcmp(name + path_size + !!path_size, key, key_size)) continue; + if (length == size) return f; + if (name[size] == '.') *group = true; + } + return b->shape->field_count; +} + +/* An object's members from json[*at] (its opening brace), in the group named + * path: a field's value, or a group's object. Strings stay where they are + * (an escaped one is unescaped over itself, which never makes it longer). + * NULL, or the error to answer. */ +static const char *members(PureJsonMessage *b, unsigned char *json, size_t size, size_t *at, const char *path, size_t path_size, + unsigned depth) { + const PureModule *m = b->module; + if (*at == size || json[(*at)++] != '{') return "json"; + *at = pure_json_space(json, *at, size); + for (bool first = true; *at < size && json[*at] != '}'; first = false) { + if (!first) { + if (json[(*at)++] != ',') return "json"; + *at = pure_json_space(json, *at, size); + } + size_t key_end = *at < size && json[*at] == '"' ? json_string_end(json + *at + 1, size - *at - 1) : 0; + if (!key_end) return "json"; + const unsigned char *key = json + *at + 1; + size_t key_size = key_end - 1; + *at = pure_json_space(json, *at + 1 + key_end, size); + if (*at == size || json[(*at)++] != ':') return "json"; + *at = pure_json_space(json, *at, size); + bool group; + uint32_t f = field_named(b, path, path_size, key, key_size, &group); + if (f == b->shape->field_count && !group && b->lenient) { /* not the app's: skipped */ + if (!skip_value(json, size, at, depth)) return "json"; + *at = pure_json_space(json, *at, size); + continue; + } + if (*at < size && json[*at] == '{') { + if (!group) return f < b->shape->field_count ? "json_type" : "json_field"; + char inner[PURE_MODULE_NAME]; + size_t inner_size = path_size + !!path_size + key_size; + memcpy(inner, path, path_size); + if (path_size) inner[path_size] = '.'; + memcpy(inner + path_size + !!path_size, key, key_size); + const char *why = members(b, json, size, at, inner, inner_size, depth + 1); + if (why) return why; + *at = pure_json_space(json, *at, size); + continue; + } + if (f == b->shape->field_count) return group ? "json_type" : "json_field"; + if (b->seen[f] || (b->given && b->given[f])) return "json_field"; + b->seen[f] = true; + const PureField *field = &m->field[b->shape->field_start + f]; + bool variable = field->type == PURE_FIELD_BYTES || field->type == PURE_FIELD_TEXT, integer; + if (*at < size && json[*at] == '"') { + size_t end = json_string_end(json + *at + 1, size - *at - 1), written; + if (!end) return "json"; + if (!variable) return "json_type"; + unsigned char *value = json + *at + 1; + if (!memchr(value, '\\', end - 1)) written = end - 1; + else if (!json_unescape(value, end - 1, value, &written)) return "json"; + if (field->type == PURE_FIELD_TEXT && !pure_utf8_valid((PureSpan){value, written})) return "json"; + write_u32(b->table + 8 * f, (uint32_t)(value - b->payload)); + write_u32(b->table + 8 * f + 4, (uint32_t)written); + *at = pure_json_space(json, *at + 1 + end, size); + continue; + } + size_t length = json_number(json + *at, size - *at, &integer); + if (!length) { + static const char *const words[] = {"true", "false", "null"}; + for (size_t w = 0; w < 3 && !length; ++w) + if (size - *at >= strlen(words[w]) && !memcmp(json + *at, words[w], strlen(words[w]))) return "json_type"; + return *at < size && json[*at] == '[' ? "json_type" : "json"; + } + if (variable || !pure_json_fixed(field, json + *at, length, b->payload)) return "json_type"; + *at = pure_json_space(json, *at + length, size); + } + if (*at == size) return "json"; + ++*at; + return NULL; +} + +const char *pure_json_message(PureJsonMessage *message, unsigned char *json, size_t size, size_t *at) { + return members(message, json, size, at, "", 0, 0); +} -- cgit v1.2.3