diff --git a/examples/huge-response/Makefile b/examples/huge-response/Makefile new file mode 100644 index 00000000..a9f764ea --- /dev/null +++ b/examples/huge-response/Makefile @@ -0,0 +1,11 @@ +PROG ?= example +CFLAGS ?= -W -Wall -Wextra -O0 -g + +all: $(PROG) + $(RUN) ./$(PROG) $(ARGS) + +$(PROG): main.c + $(CC) ../../mongoose.c -I../.. -W -Wall -DMG_ENABLE_LINES=1 $(CFLAGS) -o $(PROG) main.c mjson.c + +clean: + rm -rf $(PROG) *.o *.dSYM *.gcov *.gcno *.gcda *.obj *.exe *.ilk *.pdb diff --git a/examples/huge-response/main.c b/examples/huge-response/main.c new file mode 100644 index 00000000..ec419be9 --- /dev/null +++ b/examples/huge-response/main.c @@ -0,0 +1,90 @@ +// Copyright (c) 2021 Cesanta Software Limited +// All rights reserved +// +// Example that demonstrates how to send a large responses with limited memory. +// We're going to send a JSON array of many integer values, s_data. +// The idea is to send a response in small chunks, and let the client request +// the next chunk. +// Periodically, s_data changes, which is tracked by s_version. +// Client requests a range and a version, to ensure data integrity. +// +// 1. Start this server, type `make` +// 2. Open http://localhost:8000 in your browser + +#include "mjson.h" +#include "mongoose.h" + +static const char *s_listen_on = "http://localhost:8000"; +static const char *s_root_dir = "web_root"; + +#define DATA_SIZE 10000 // Total number of elements +#define CHUNK_SIZE 1000 // Max number returned in one API call +static int s_data[DATA_SIZE]; // Simulate some complex big dataMax number + // returned in one API call +static unsigned s_version = 0; // Data "version" + +static double getparam(struct mg_http_message *hm, const char *json_path) { + double dv = 0; + mjson_get_number(hm->body.ptr, hm->body.len, json_path, &dv); + return dv; +} + +static void fn(struct mg_connection *c, int ev, void *ev_data, void *fn_data) { + if (ev == MG_EV_HTTP_MSG) { + struct mg_http_message *hm = ev_data; + if (mg_http_match_uri(hm, "/api/data")) { + unsigned start = getparam(hm, "$.start"); + unsigned version = getparam(hm, "$.version"); + char *response = NULL; + if (version > 0 && version != s_version) { + // Version mismatch: s_data has changed while client fetches it + // Tell client to restart + response = mjson_aprintf("{%Q:%Q, %Q:%u}", "error", "wrong version", + "version", version); + } else { + // Return data, up to CHUNK_SIZE elements + unsigned max = start + CHUNK_SIZE; + const char *comma = ""; + if (max > DATA_SIZE) max = DATA_SIZE; + mjson_printf(mjson_print_dynamic_buf, &response, "{%Q:%u,%Q:%u,%Q:[", + "version", s_version, "start", start, "data"); + while (start < max) { + mjson_printf(mjson_print_dynamic_buf, &response, "%s%d", comma, + s_data[start]); + comma = ","; + start++; + } + mjson_printf(mjson_print_dynamic_buf, &response, "]}"); + } + mg_http_reply(c, 200, "Content-Type: text/json\r\n", "%s", response); + free(response); + } else { + struct mg_http_serve_opts opts = {0}; + opts.root_dir = s_root_dir; + mg_http_serve_dir(c, hm, &opts); + } + } + (void) fn_data; +} + +static void timer_fn(void *arg) { + for (int i = 0; i < DATA_SIZE; i++) { + s_data[i] = rand(); + } + s_version++; + (void) arg; +} + +int main(void) { + struct mg_mgr mgr; + struct mg_timer t1; + mg_mgr_init(&mgr); + srand(time(NULL)); + mg_timer_init(&t1, 1000, MG_TIMER_REPEAT | MG_TIMER_RUN_NOW, timer_fn, NULL); + mg_http_listen(&mgr, s_listen_on, fn, NULL); + LOG(LL_INFO, ("Listening on %s", s_listen_on)); + for (;;) mg_mgr_poll(&mgr, 1000); + mg_timer_free(&t1); + mg_mgr_free(&mgr); + return 0; +} diff --git a/examples/huge-response/mjson.c b/examples/huge-response/mjson.c new file mode 100644 index 00000000..4ed7858f --- /dev/null +++ b/examples/huge-response/mjson.c @@ -0,0 +1,1066 @@ +// Copyright (c) 2018-2020 Cesanta Software Limited +// All rights reserved +// +// Permission is hereby granted, free of charge, to any person obtaining a copy +// of this software and associated documentation files (the "Software"), to deal +// in the Software without restriction, including without limitation the rights +// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell +// copies of the Software, and to permit persons to whom the Software is +// furnished to do so, subject to the following conditions: +// +// The above copyright notice and this permission notice shall be included in +// all copies or substantial portions of the Software. +// +// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR +// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, +// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE +// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER +// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, +// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE +// SOFTWARE. + +#include +#include + +#include "mjson.h" + +#if defined(_MSC_VER) +#define alloca(x) _alloca(x) +#endif + +#if defined(_MSC_VER) && _MSC_VER < 1700 +#define va_copy(x, y) (x) = (y) +#define isinf(x) !_finite(x) +#define isnan(x) _isnan(x) +#endif + +static double mystrtod(const char *str, char **end); + +static int mjson_esc(int c, int esc) { + const char *p, *esc1 = "\b\f\n\r\t\\\"", *esc2 = "bfnrt\\\""; + for (p = esc ? esc1 : esc2; *p != '\0'; p++) { + if (*p == c) return esc ? esc2[p - esc1] : esc1[p - esc2]; + } + return 0; +} + +static int mjson_escape(int c) { + return mjson_esc(c, 1); +} + +static int mjson_pass_string(const char *s, int len) { + int i; + for (i = 0; i < len; i++) { + if (s[i] == '\\' && i + 1 < len && mjson_escape(s[i + 1])) { + i++; + } else if (s[i] == '\0') { + return MJSON_ERROR_INVALID_INPUT; + } else if (s[i] == '"') { + return i; + } + } + return MJSON_ERROR_INVALID_INPUT; +} + +int mjson(const char *s, int len, mjson_cb_t cb, void *ud) { + enum { S_VALUE, S_KEY, S_COLON, S_COMMA_OR_EOO } expecting = S_VALUE; + unsigned char nesting[MJSON_MAX_DEPTH]; + int i, depth = 0; +#define MJSONCALL(ev) \ + if (cb != NULL && cb(ev, s, start, i - start + 1, ud)) return i + 1; + +// In the ascii table, the distance between `[` and `]` is 2. +// Ditto for `{` and `}`. Hence +2 in the code below. +#define MJSONEOO() \ + do { \ + if (c != nesting[depth - 1] + 2) return MJSON_ERROR_INVALID_INPUT; \ + depth--; \ + if (depth == 0) { \ + MJSONCALL(tok); \ + return i + 1; \ + } \ + } while (0) + + for (i = 0; i < len; i++) { + int start = i; + unsigned char c = ((unsigned char *) s)[i]; + int tok = c; + if (c == ' ' || c == '\t' || c == '\n' || c == '\r') continue; + // printf("- %c [%.*s] %d %d\n", c, i, s, depth, expecting); + switch (expecting) { + case S_VALUE: + if (c == '{') { + if (depth >= (int) sizeof(nesting)) return MJSON_ERROR_TOO_DEEP; + nesting[depth++] = c; + expecting = S_KEY; + break; + } else if (c == '[') { + if (depth >= (int) sizeof(nesting)) return MJSON_ERROR_TOO_DEEP; + nesting[depth++] = c; + break; + } else if (c == ']' && depth > 0) { // Empty array + MJSONEOO(); + } else if (c == 't' && i + 3 < len && memcmp(&s[i], "true", 4) == 0) { + i += 3; + tok = MJSON_TOK_TRUE; + } else if (c == 'n' && i + 3 < len && memcmp(&s[i], "null", 4) == 0) { + i += 3; + tok = MJSON_TOK_NULL; + } else if (c == 'f' && i + 4 < len && memcmp(&s[i], "false", 5) == 0) { + i += 4; + tok = MJSON_TOK_FALSE; + } else if (c == '-' || ((c >= '0' && c <= '9'))) { + char *end = NULL; + mystrtod(&s[i], &end); + if (end != NULL) i += (int) (end - &s[i] - 1); + tok = MJSON_TOK_NUMBER; + } else if (c == '"') { + int n = mjson_pass_string(&s[i + 1], len - i - 1); + if (n < 0) return n; + i += n + 1; + tok = MJSON_TOK_STRING; + } else { + return MJSON_ERROR_INVALID_INPUT; + } + if (depth == 0) { + MJSONCALL(tok); + return i + 1; + } + expecting = S_COMMA_OR_EOO; + break; + + case S_KEY: + if (c == '"') { + int n = mjson_pass_string(&s[i + 1], len - i - 1); + if (n < 0) return n; + i += n + 1; + tok = MJSON_TOK_KEY; + expecting = S_COLON; + } else if (c == '}') { // Empty object + MJSONEOO(); + expecting = S_COMMA_OR_EOO; + } else { + return MJSON_ERROR_INVALID_INPUT; + } + break; + + case S_COLON: + if (c == ':') { + expecting = S_VALUE; + } else { + return MJSON_ERROR_INVALID_INPUT; + } + break; + + case S_COMMA_OR_EOO: + if (depth <= 0) return MJSON_ERROR_INVALID_INPUT; + if (c == ',') { + expecting = (nesting[depth - 1] == '{') ? S_KEY : S_VALUE; + } else if (c == ']' || c == '}') { + MJSONEOO(); + } else { + return MJSON_ERROR_INVALID_INPUT; + } + break; + } + MJSONCALL(tok); + } + return MJSON_ERROR_INVALID_INPUT; +} + +struct msjon_get_data { + const char *path; // Lookup json path + int pos; // Current path position + int d1; // Current depth of traversal + int d2; // Expected depth of traversal + int i1; // Index in an array + int i2; // Expected index in an array + int obj; // If the value is array/object, offset where it starts + const char **tokptr; // Destination + int *toklen; // Destination length + int tok; // Returned token +}; + +#include + +static int plen1(const char *s) { + int i = 0, n = 0; + while (s[i] != '\0' && s[i] != '.' && s[i] != '[') + n++, i += s[i] == '\\' ? 2 : 1; + // printf("PLEN: s: [%s], [%.*s] => %d\n", s, i, s, n); + return n; +} + +static int plen2(const char *s) { + int i = 0, n = 0; + while (s[i] != '\0' && s[i] != '.' && s[i] != '[') + n++, i += s[i] == '\\' ? 2 : 1; + // printf("PLEN: s: [%s], [%.*s] => %d\n", s, i, s, n); + return i; +} + +static int kcmp(const char *a, const char *b, int n) { + int i = 0, j = 0, r = 0; + for (i = 0, j = 0; j < n; i++, j++) { + if (b[i] == '\\') i++; + if ((r = a[j] - b[i]) != 0) return r; + } + // printf("KCMP: a: [%.*s], b:[%.*s] ==> %d\n", n, a, i, b, r); + return r; +} + +static int mjson_get_cb(int tok, const char *s, int off, int len, void *ud) { + struct msjon_get_data *d = (struct msjon_get_data *) ud; +#if 0 + printf("--> %2x %2d %2d %2d %2d\t %2d %2d\t'%s' '%s' '%s' '%s'\n", tok, d->d1, + d->d2, d->i1, d->i2, (int) off, (int) d->pos, s, d->path, s + off, + d->path + d->pos); +#endif + if (d->tok != MJSON_TOK_INVALID) return 1; // Found + if (tok == '{' || tok == '[') { + if (d->d1 < d->d2) d->obj = -1; + if (d->d1 == d->d2) d->obj = off; + if (d->d1 == d->d2 && tok == '[' && d->path[d->pos] == '[') { + d->i1 = 0; + d->i2 = (int) mystrtod(&d->path[d->pos + 1], NULL); + if (d->i1 == d->i2) { + while (d->path[d->pos] && d->path[d->pos] != ']') d->pos++; + if (d->path[d->pos] == ']') d->pos++; + d->d2++; + } + } + d->d1++; + } else if (tok == '}' || tok == ']') { + if (tok == ']' && d->d1 == d->d2) d->i1 = 0; + d->d1--; + // printf("X %s %d %d %d %d %d\n", d->path + d->pos, d->d1, d->d2, d->i1, + // d->i2, d->obj); + if (!d->path[d->pos] && d->d1 == d->d2 && d->obj != -1) { + d->tok = tok - 2; + if (d->tokptr) *d->tokptr = s + d->obj; + if (d->toklen) *d->toklen = off - d->obj + 1; + return 1; + } + } else if (tok == ',' && d->d1 == d->d2 && d->pos && + d->path[d->pos - 1] == ']') { + return 1; // Not found in the current elem array + } else if (tok == ',' && d->d1 == d->d2 + 1 && d->path[d->pos] == '[') { + // printf("GG '%s' '%s'\n", d->path, &d->path[d->pos]); + d->i1++; + if (d->i1 == d->i2) { + while (d->path[d->pos] && d->path[d->pos] != ']') d->pos++; + if (d->path[d->pos] == ']') d->pos++; + d->d2++; + } + } else if (tok == MJSON_TOK_KEY && d->d1 == d->d2 + 1 && + d->path[d->pos] == '.' && s[off] == '"' && + s[off + len - 1] == '"' && + plen1(&d->path[d->pos + 1]) == len - 2 && + kcmp(s + off + 1, &d->path[d->pos + 1], len - 2) == 0) { + d->d2++; + d->pos += plen2(&d->path[d->pos + 1]) + 1; + } else if (tok == MJSON_TOK_KEY && d->d1 == d->d2) { + return 1; // Exhausted path, not found + } else if (MJSON_TOK_IS_VALUE(tok)) { + // printf("T %d %d %d %d %d\n", tok, d->d1, d->d2, d->i1, d->i2); + if (d->d1 == d->d2 && d->i1 == d->i2 && !d->path[d->pos]) { + d->tok = tok; + if (d->tokptr) *d->tokptr = s + off; + if (d->toklen) *d->toklen = len; + return 1; + } + } + return 0; +} + +int mjson_find(const char *s, int n, const char *jp, const char **tp, int *tl) { + struct msjon_get_data data = {jp, 1, 0, 0, 0, + 0, -1, tp, tl, MJSON_TOK_INVALID}; + if (jp[0] != '$') return MJSON_TOK_INVALID; + if (mjson(s, n, mjson_get_cb, &data) < 0) return MJSON_TOK_INVALID; + return data.tok; +} + +int mjson_get_number(const char *s, int len, const char *path, double *v) { + const char *p; + int tok, n; + if ((tok = mjson_find(s, len, path, &p, &n)) == MJSON_TOK_NUMBER) { + if (v != NULL) *v = mystrtod(p, NULL); + } + return tok == MJSON_TOK_NUMBER ? 1 : 0; +} + +int mjson_get_bool(const char *s, int len, const char *path, int *v) { + int tok = mjson_find(s, len, path, NULL, NULL); + if (tok == MJSON_TOK_TRUE && v != NULL) *v = 1; + if (tok == MJSON_TOK_FALSE && v != NULL) *v = 0; + return tok == MJSON_TOK_TRUE || tok == MJSON_TOK_FALSE ? 1 : 0; +} + +static unsigned char unhex(unsigned char c) { + return (c >= '0' && c <= '9') ? (unsigned char) (c - '0') + : (c >= 'A' && c <= 'F') ? (unsigned char) (c - '7') + : (unsigned char) (c - 'W'); +} + +static unsigned char mjson_unhex_nimble(const char *s) { + return (unsigned char) (unhex(((unsigned char *) s)[0]) << 4) | + unhex(((unsigned char *) s)[1]); +} + +static int mjson_unescape(const char *s, int len, char *to, int n) { + int i, j; + for (i = 0, j = 0; i < len && j < n; i++, j++) { + if (s[i] == '\\' && i + 5 < len && s[i + 1] == 'u') { + // \uXXXX escape. We could process a simple one-byte chars + // \u00xx from the ASCII range. More complex chars would require + // dragging in a UTF8 library, which is too much for us + if (s[i + 2] != '0' || s[i + 3] != '0') return -1; // Too much, give up + ((unsigned char *) to)[j] = mjson_unhex_nimble(s + i + 4); + i += 5; + } else if (s[i] == '\\' && i + 1 < len) { + int c = mjson_esc(s[i + 1], 0); + if (c == 0) return -1; + to[j] = (char) (unsigned char) c; + i++; + } else { + to[j] = s[i]; + } + } + if (j >= n) return -1; + if (n > 0) to[j] = '\0'; + return j; +} + +int mjson_get_string(const char *s, int len, const char *path, char *to, + int n) { + const char *p; + int sz; + if (mjson_find(s, len, path, &p, &sz) != MJSON_TOK_STRING) return -1; + return mjson_unescape(p + 1, sz - 2, to, n); +} + +int mjson_get_hex(const char *s, int len, const char *x, char *to, int n) { + const char *p; + int i, j, sz; + if (mjson_find(s, len, x, &p, &sz) != MJSON_TOK_STRING) return -1; + for (i = j = 0; i < sz - 3 && j < n; i += 2, j++) { + ((unsigned char *) to)[j] = mjson_unhex_nimble(p + i + 1); + } + if (j < n) to[j] = '\0'; + return j; +} + +#if MJSON_ENABLE_BASE64 +static unsigned char mjson_base64rev(int c) { + if (c >= 'A' && c <= 'Z') { + return (unsigned char) (c - 'A'); + } else if (c >= 'a' && c <= 'z') { + return (unsigned char) (c + 26 - 'a'); + } else if (c >= '0' && c <= '9') { + return (unsigned char) (c + 52 - '0'); + } else if (c == '+') { + return 62; + } else if (c == '/') { + return 63; + } else { + return 64; + } +} + +int mjson_base64_dec(const char *src, int n, char *dst, int dlen) { + const char *end = src + n; + int len = 0; + while (src + 3 < end && len < dlen) { + unsigned char a = mjson_base64rev(src[0]), b = mjson_base64rev(src[1]), + c = mjson_base64rev(src[2]), d = mjson_base64rev(src[3]); + dst[len++] = (char) (unsigned char) ((a << 2) | (b >> 4)); + if (src[2] != '=' && len < dlen) { + dst[len++] = (char) (unsigned char) ((b << 4) | (c >> 2)); + if (src[3] != '=' && len < dlen) { + dst[len++] = (char) (unsigned char) ((c << 6) | d); + } + } + src += 4; + } + if (len < dlen) dst[len] = '\0'; + return len; +} + +int mjson_get_base64(const char *s, int len, const char *path, char *to, + int n) { + const char *p; + int sz; + if (mjson_find(s, len, path, &p, &sz) != MJSON_TOK_STRING) return 0; + return mjson_base64_dec(p + 1, sz - 2, to, n); +} +#endif // MJSON_ENABLE_BASE64 + +#if MJSON_ENABLE_NEXT +struct nextdata { + int off, len, depth, t, vo, arrayindex; + int *koff, *klen, *voff, *vlen, *vtype; +}; + +static int next_cb(int tok, const char *s, int off, int len, void *ud) { + struct nextdata *d = (struct nextdata *) ud; + // int i; + switch (tok) { + case '{': + case '[': + if (d->depth == 0 && tok == '[') d->arrayindex = 0; + if (d->depth == 1 && off > d->off) { + d->vo = off; + d->t = tok == '{' ? MJSON_TOK_OBJECT : MJSON_TOK_ARRAY; + if (d->voff) *d->voff = off; + if (d->vtype) *d->vtype = d->t; + } + d->depth++; + break; + case '}': + case ']': + d->depth--; + if (d->depth == 1 && d->vo) { + d->len = off + len; + if (d->vlen) *d->vlen = d->len - d->vo; + if (d->arrayindex >= 0) { + if (d->koff) *d->koff = d->arrayindex; // koff holds array index + if (d->klen) *d->klen = 0; // klen holds 0 + } + return 1; + } + if (d->depth == 1 && d->arrayindex >= 0) d->arrayindex++; + break; + case ',': + case ':': + break; + case MJSON_TOK_KEY: + if (d->depth == 1 && d->off < off) { + if (d->koff) *d->koff = off; // And report back to the user + if (d->klen) *d->klen = len; // If we have to + } + break; + default: + if (d->depth != 1) break; + // If we're iterating over the array + if (off > d->off) { + d->len = off + len; + if (d->vlen) *d->vlen = len; // value length + if (d->voff) *d->voff = off; // value offset + if (d->vtype) *d->vtype = tok; // value type + if (d->arrayindex >= 0) { + if (d->koff) *d->koff = d->arrayindex; // koff holds array index + if (d->klen) *d->klen = 0; // klen holds 0 + } + return 1; + } + if (d->arrayindex >= 0) d->arrayindex++; + break; + } + (void) s; + return 0; +} + +int mjson_next(const char *s, int n, int off, int *koff, int *klen, int *voff, + int *vlen, int *vtype) { + struct nextdata d = {off, 0, 0, 0, 0, -1, koff, klen, voff, vlen, vtype}; + mjson(s, n, next_cb, &d); + return d.len; +} +#endif + +#if MJSON_ENABLE_PRINT +int mjson_print_fixed_buf(const char *ptr, int len, void *fndata) { + struct mjson_fixedbuf *fb = (struct mjson_fixedbuf *) fndata; + int i, left = fb->size - 1 - fb->len; + if (left < len) len = left; + for (i = 0; i < len; i++) fb->ptr[fb->len + i] = ptr[i]; + fb->len += len; + fb->ptr[fb->len] = '\0'; + return len; +} + +// This function allocates memory in chunks of size MJSON_DYNBUF_CHUNK +// to decrease memory fragmentation, when many calls are executed to +// print e.g. a base64 string or a hex string. +int mjson_print_dynamic_buf(const char *ptr, int len, void *fndata) { + char *s, *buf = *(char **) fndata; + size_t curlen = buf == NULL ? 0 : strlen(buf); + size_t new_size = curlen + (size_t) len + 1 + MJSON_DYNBUF_CHUNK; + new_size -= new_size % MJSON_DYNBUF_CHUNK; + + if ((s = (char *) realloc(buf, new_size)) == NULL) { + return 0; + } else { + memcpy(s + curlen, ptr, (size_t) len); + s[curlen + (size_t) len] = '\0'; + *(char **) fndata = s; + return len; + } +} + +int mjson_snprintf(char *buf, size_t len, const char *fmt, ...) { + va_list ap; + struct mjson_fixedbuf fb = {buf, (int) len, 0}; + va_start(ap, fmt); + mjson_vprintf(mjson_print_fixed_buf, &fb, fmt, &ap); + va_end(ap); + return fb.len; +} + +char *mjson_aprintf(const char *fmt, ...) { + va_list ap; + char *result = NULL; + va_start(ap, fmt); + mjson_vprintf(mjson_print_dynamic_buf, &result, fmt, &ap); + va_end(ap); + return result; +} + +int mjson_print_null(const char *ptr, int len, void *userdata) { + (void) ptr; + (void) userdata; + return len; +} + +int mjson_print_buf(mjson_print_fn_t fn, void *fnd, const char *buf, int len) { + return fn(buf, len, fnd); +} + +int mjson_print_long(mjson_print_fn_t fn, void *fnd, long val, int is_signed) { + unsigned long v = (unsigned long) val, s = 0, n, i; + char buf[20], t; + if (is_signed && val < 0) buf[s++] = '-', v = (unsigned long) (-val); + // This loop prints a number in reverse order. I guess this is because we + // write numbers from right to left: least significant digit comes last. + // Maybe because we use Arabic numbers, and Arabs write RTL? + for (n = 0; v > 0; v /= 10) buf[s + n++] = "0123456789"[v % 10]; + // Reverse a string + for (i = 0; i < n / 2; i++) + t = buf[s + i], buf[s + i] = buf[s + n - i - 1], buf[s + n - i - 1] = t; + if (val == 0) buf[n++] = '0'; // Handle special case + return fn(buf, (int) (s + n), fnd); +} + +int mjson_print_int(mjson_print_fn_t fn, void *fnd, int v, int s) { + return mjson_print_long(fn, fnd, s ? (long) v : (long) (unsigned) v, s); +} + +static int addexp(char *buf, int e, int sign) { + int n = 0; + buf[n++] = 'e'; + buf[n++] = (char) sign; + if (e > 400) return 0; + if (e < 10) buf[n++] = '0'; + if (e >= 100) buf[n++] = (char) (e / 100 + '0'), e -= 100 * (e / 100); + if (e >= 10) buf[n++] = (char) (e / 10 + '0'), e -= 10 * (e / 10); + buf[n++] = (char) (e + '0'); + return n; +} + +int mjson_print_dbl(mjson_print_fn_t fn, void *fnd, double d, int width) { + char buf[40]; + int i, s = 0, n = 0, e = 0; + double t, mul, saved; + if (d == 0.0) return fn("0", 1, fnd); + if (isinf(d)) return fn(d > 0 ? "inf" : "-inf", d > 0 ? 3 : 4, fnd); + if (isnan(d)) return fn("nan", 3, fnd); + if (d < 0.0) d = -d, buf[s++] = '-'; + + // Round + saved = d; + mul = 1.0; + while (d >= 10.0 && d / mul >= 10.0) mul *= 10.0; + while (d <= 1.0 && d / mul <= 1.0) mul /= 10.0; + for (i = 0, t = mul * 5; i < width; i++) t /= 10.0; + d += t; + // Calculate exponent, and 'mul' for scientific representation + mul = 1.0; + while (d >= 10.0 && d / mul >= 10.0) mul *= 10.0, e++; + while (d < 1.0 && d / mul < 1.0) mul /= 10.0, e--; + // printf(" --> %g %d %g %g\n", saved, e, t, mul); + + if (e >= width) { + struct mjson_fixedbuf fb = {buf + s, (int) sizeof(buf) - s, 0}; + n = mjson_print_dbl(mjson_print_fixed_buf, &fb, saved / mul, width); + // printf(" --> %.*g %d [%.*s]\n", 10, d / t, e, fb.len, fb.ptr); + n += addexp(buf + s + n, e, '+'); + return fn(buf, s + n, fnd); + } else if (e <= -width) { + struct mjson_fixedbuf fb = {buf + s, (int) sizeof(buf) - s, 0}; + n = mjson_print_dbl(mjson_print_fixed_buf, &fb, saved / mul, width); + // printf(" --> %.*g %d [%.*s]\n", 10, d / mul, e, fb.len, fb.ptr); + n += addexp(buf + s + n, -e, '-'); + return fn(buf, s + n, fnd); + } else { + for (i = 0, t = mul; t >= 1.0 && s + n < (int) sizeof(buf); i++) { + int ch = (int) (d / t); + if (n > 0 || ch > 0) buf[s + n++] = (char) (ch + '0'); + d -= ch * t; + t /= 10.0; + } + // printf(" --> [%g] -> %g %g (%d) [%.*s]\n", saved, d, t, n, s + n, buf); + if (n == 0) buf[s++] = '0'; + while (t >= 1.0 && n + s < (int) sizeof(buf)) buf[n++] = '0', t /= 10.0; + if (s + n < (int) sizeof(buf)) buf[n + s++] = '.'; + // printf(" 1--> [%g] -> [%.*s]\n", saved, s + n, buf); + for (i = 0, t = 0.1; s + n < (int) sizeof(buf) && n < width; i++) { + int ch = (int) (d / t); + buf[s + n++] = (char) (ch + '0'); + d -= ch * t; + t /= 10.0; + } + } + while (n > 0 && buf[s + n - 1] == '0') n--; // Trim trailing zeros + if (n > 0 && buf[s + n - 1] == '.') n--; // Trim trailing dot + buf[s + n] = '\0'; + return fn(buf, s + n, fnd); +} + +int mjson_print_str(mjson_print_fn_t fn, void *fnd, const char *s, int len) { + int i, n = fn("\"", 1, fnd); + for (i = 0; i < len; i++) { + char c = (char) (unsigned char) mjson_escape(s[i]); + if (c) { + n += fn("\\", 1, fnd); + n += fn(&c, 1, fnd); + } else { + n += fn(&s[i], 1, fnd); + } + } + return n + fn("\"", 1, fnd); +} + +#if MJSON_ENABLE_BASE64 +int mjson_print_b64(mjson_print_fn_t fn, void *fnd, const unsigned char *s, + int n) { + const char *t = + "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"; + int i, len = fn("\"", 1, fnd); + for (i = 0; i < n; i += 3) { + int a = s[i], b = i + 1 < n ? s[i + 1] : 0, c = i + 2 < n ? s[i + 2] : 0; + char buf[4] = {t[a >> 2], t[(a & 3) << 4 | (b >> 4)], '=', '='}; + if (i + 1 < n) buf[2] = t[(b & 15) << 2 | (c >> 6)]; + if (i + 2 < n) buf[3] = t[c & 63]; + len += fn(buf, sizeof(buf), fnd); + } + return len + fn("\"", 1, fnd); +} +#endif /* MJSON_ENABLE_BASE64 */ + +int mjson_vprintf(mjson_print_fn_t fn, void *fnd, const char *fmt, + va_list *ap) { + int i = 0, n = 0; + while (fmt[i] != '\0') { + if (fmt[i] == '%') { + char fc = fmt[++i]; + int is_long = 0; + if (fc == 'l') { + is_long = 1; + fc = fmt[i + 1]; + } + if (fc == 'Q') { + char *buf = va_arg(*ap, char *); + n += mjson_print_str(fn, fnd, buf ? buf : "", + buf ? (int) strlen(buf) : 0); + } else if (strncmp(&fmt[i], ".*Q", 3) == 0) { + int len = va_arg(*ap, int); + char *buf = va_arg(*ap, char *); + n += mjson_print_str(fn, fnd, buf, len); + i += 2; + } else if (fc == 'd' || fc == 'u') { + int is_signed = (fc == 'd'); + if (is_long) { + long val = va_arg(*ap, long); + n += mjson_print_long(fn, fnd, val, is_signed); + i++; + } else { + int val = va_arg(*ap, int); + n += mjson_print_int(fn, fnd, val, is_signed); + } + } else if (fc == 'B') { + const char *s = va_arg(*ap, int) ? "true" : "false"; + n += mjson_print_buf(fn, fnd, s, (int) strlen(s)); + } else if (fc == 's') { + char *buf = va_arg(*ap, char *); + n += mjson_print_buf(fn, fnd, buf, (int) strlen(buf)); + } else if (strncmp(&fmt[i], ".*s", 3) == 0) { + int len = va_arg(*ap, int); + char *buf = va_arg(*ap, char *); + n += mjson_print_buf(fn, fnd, buf, len); + i += 2; + } else if (fc == 'g') { + n += mjson_print_dbl(fn, fnd, va_arg(*ap, double), 6); + } else if (strncmp(&fmt[i], ".*g", 3) == 0) { + int width = va_arg(*ap, int); + n += mjson_print_dbl(fn, fnd, va_arg(*ap, double), width); + i += 2; +#if MJSON_ENABLE_BASE64 + } else if (fc == 'V') { + int len = va_arg(*ap, int); + const char *buf = va_arg(*ap, const char *); + n += mjson_print_b64(fn, fnd, (unsigned char *) buf, len); +#endif + } else if (fc == 'H') { + const char *hex = "0123456789abcdef"; + int j, len = va_arg(*ap, int); + const unsigned char *p = va_arg(*ap, const unsigned char *); + n += fn("\"", 1, fnd); + for (j = 0; j < len; j++) { + n += fn(&hex[(p[j] >> 4) & 15], 1, fnd); + n += fn(&hex[p[j] & 15], 1, fnd); + } + n += fn("\"", 1, fnd); + } else if (fc == 'M') { + mjson_vprint_fn_t vfn = va_arg(*ap, mjson_vprint_fn_t); + n += vfn(fn, fnd, ap); + } + i++; + } else { + n += mjson_print_buf(fn, fnd, &fmt[i++], 1); + } + } + return n; +} + +int mjson_printf(mjson_print_fn_t fn, void *fnd, const char *fmt, ...) { + va_list ap; + int len; + va_start(ap, fmt); + len = mjson_vprintf(fn, fnd, fmt, &ap); + va_end(ap); + return len; +} +#endif /* MJSON_ENABLE_PRINT */ + +static int is_digit(int c) { + return c >= '0' && c <= '9'; +} + +/* NOTE: strtod() implementation by Yasuhiro Matsumoto. */ +static double mystrtod(const char *str, char **end) { + double d = 0.0; + int sign = 1, n = 0; + const char *p = str, *a = str; + + /* decimal part */ + if (*p == '-') { + sign = -1; + ++p; + } else if (*p == '+') { + ++p; + } + if (is_digit(*p)) { + d = (double) (*p++ - '0'); + while (*p && is_digit(*p)) { + d = d * 10.0 + (double) (*p - '0'); + ++p; + ++n; + } + a = p; + } else if (*p != '.') { + goto done; + } + d *= sign; + + /* fraction part */ + if (*p == '.') { + double f = 0.0; + double base = 0.1; + ++p; + + if (is_digit(*p)) { + while (*p && is_digit(*p)) { + f += base * (*p - '0'); + base /= 10.0; + ++p; + ++n; + } + } + d += f * sign; + a = p; + } + + /* exponential part */ + if ((*p == 'E') || (*p == 'e')) { + int i, e = 0, neg = 0; + p++; + if (*p == '-') p++, neg++; + if (*p == '+') p++; + while (is_digit(*p)) e = e * 10 + *p++ - '0'; + if (neg) e = -e; +#if 0 + if (d == 2.2250738585072011 && e == -308) { + d = 0.0; + a = p; + goto done; + } + if (d == 2.2250738585072012 && e <= -308) { + d *= 1.0e-308; + a = p; + goto done; + } +#endif + for (i = 0; i < e; i++) d *= 10; + for (i = 0; i < -e; i++) d /= 10; + a = p; + } else if (p > str && !is_digit(*(p - 1))) { + a = str; + goto done; + } + +done: + if (end) *end = (char *) a; + return d; +} + +#if MJSON_ENABLE_MERGE +int mjson_merge(const char *s, int n, const char *s2, int n2, + mjson_print_fn_t fn, void *userdata) { + int koff, klen, voff, vlen, t, t2, k, off = 0, len = 0, comma = 0; + if (n < 2) return len; + len += fn("{", 1, userdata); + while ((off = mjson_next(s, n, off, &koff, &klen, &voff, &vlen, &t)) != 0) { + char *path = (char *) alloca((size_t) klen + 1); + const char *val; + memcpy(path, "$.", 2); + memcpy(path + 2, s + koff + 1, (size_t) (klen - 2)); + path[klen] = '\0'; + if ((t2 = mjson_find(s2, n2, path, &val, &k)) != MJSON_TOK_INVALID) { + if (t2 == MJSON_TOK_NULL) continue; // null deletes the key + } else { + val = s + voff; // Key is not found in the update. Copy the old value. + } + if (comma) len += fn(",", 1, userdata); + len += fn(s + koff, klen, userdata); + len += fn(":", 1, userdata); + if (t == MJSON_TOK_OBJECT && t2 == MJSON_TOK_OBJECT) { + len += mjson_merge(s + voff, vlen, val, k, fn, userdata); + } else { + if (t2 != MJSON_TOK_INVALID) vlen = k; + len += fn(val, vlen, userdata); + } + comma = 1; + } + // Add missing keys + off = 0; + while ((off = mjson_next(s2, n2, off, &koff, &klen, &voff, &vlen, &t)) != 0) { + char *path = (char *) alloca((size_t) klen + 1); + const char *val; + if (t == MJSON_TOK_NULL) continue; + memcpy(path, "$.", 2); + memcpy(path + 2, s2 + koff + 1, (size_t) (klen - 2)); + path[klen] = '\0'; + if (mjson_find(s, n, path, &val, &vlen) != MJSON_TOK_INVALID) continue; + if (comma) len += fn(",", 1, userdata); + len += fn(s2 + koff, klen, userdata); + len += fn(":", 1, userdata); + len += fn(s2 + voff, vlen, userdata); + comma = 1; + } + len += fn("}", 1, userdata); + return len; +} +#endif // MJSON_ENABLE_MERGE + +#if MJSON_ENABLE_PRETTY +struct prettydata { + int level; + int len; + int prev; + const char *pad; + int padlen; + mjson_print_fn_t fn; + void *userdata; +}; + +static int pretty_cb(int ev, const char *s, int off, int len, void *ud) { + struct prettydata *d = (struct prettydata *) ud; + int i; + switch (ev) { + case '{': + case '[': + d->level++; + d->len += d->fn(s + off, len, d->userdata); + break; + case '}': + case ']': + d->level--; + if (d->prev != '[' && d->prev != '{' && d->padlen > 0) { + d->len += d->fn("\n", 1, d->userdata); + for (i = 0; i < d->level; i++) + d->len += d->fn(d->pad, d->padlen, d->userdata); + } + d->len += d->fn(s + off, len, d->userdata); + break; + case ',': + d->len += d->fn(s + off, len, d->userdata); + if (d->padlen > 0) { + d->len += d->fn("\n", 1, d->userdata); + for (i = 0; i < d->level; i++) + d->len += d->fn(d->pad, d->padlen, d->userdata); + } + break; + case ':': + d->len += d->fn(s + off, len, d->userdata); + if (d->padlen > 0) d->len += d->fn(" ", 1, d->userdata); + break; + case MJSON_TOK_KEY: + if (d->prev == '{' && d->padlen > 0) { + d->len += d->fn("\n", 1, d->userdata); + for (i = 0; i < d->level; i++) + d->len += d->fn(d->pad, d->padlen, d->userdata); + } + d->len += d->fn(s + off, len, d->userdata); + break; + default: + if (d->prev == '[' && d->padlen > 0) { + d->len += d->fn("\n", 1, d->userdata); + for (i = 0; i < d->level; i++) + d->len += d->fn(d->pad, d->padlen, d->userdata); + } + d->len += d->fn(s + off, len, d->userdata); + break; + } + d->prev = ev; + return 0; +} + +int mjson_pretty(const char *s, int n, const char *pad, mjson_print_fn_t fn, + void *userdata) { + struct prettydata d = {0, 0, 0, pad, (int) strlen(pad), fn, userdata}; + if (mjson(s, n, pretty_cb, &d) < 0) return -1; + return d.len; +} +#endif // MJSON_ENABLE_PRETTY + +#if MJSON_ENABLE_RPC +struct jsonrpc_ctx jsonrpc_default_context; + +int mjson_globmatch(const char *s1, int n1, const char *s2, int n2) { + int i = 0, j = 0, ni = 0, nj = 0; + while (i < n1 || j < n2) { + if (i < n1 && j < n2 && (s1[i] == '?' || s2[j] == s1[i])) { + i++, j++; + } else if (i < n1 && (s1[i] == '*' || s1[i] == '#')) { + ni = i, nj = j + 1, i++; + } else if (nj > 0 && nj <= n2 && (s1[i - 1] == '#' || s2[j] != '/')) { + i = ni, j = nj; + } else { + return 0; + } + } + return 1; +} + +void jsonrpc_return_errorv(struct jsonrpc_request *r, int code, + const char *message, const char *data_fmt, + va_list *ap) { + if (r->id_len == 0) return; + mjson_printf(r->fn, r->fndata, + "{\"id\":%.*s,\"error\":{\"code\":%d,\"message\":%Q", r->id_len, + r->id, code, message == NULL ? "" : message); + if (data_fmt != NULL) { + mjson_printf(r->fn, r->fndata, ",\"data\":"); + mjson_vprintf(r->fn, r->fndata, data_fmt, ap); + } + mjson_printf(r->fn, r->fndata, "}}\n"); +} + +void jsonrpc_return_error(struct jsonrpc_request *r, int code, + const char *message, const char *data_fmt, ...) { + va_list ap; + va_start(ap, data_fmt); + jsonrpc_return_errorv(r, code, message, data_fmt, &ap); + va_end(ap); +} + +void jsonrpc_return_successv(struct jsonrpc_request *r, const char *result_fmt, + va_list *ap) { + if (r->id_len == 0) return; + mjson_printf(r->fn, r->fndata, "{\"id\":%.*s,\"result\":", r->id_len, r->id); + if (result_fmt != NULL) { + mjson_vprintf(r->fn, r->fndata, result_fmt, ap); + } else { + mjson_printf(r->fn, r->fndata, "%s", "null"); + } + mjson_printf(r->fn, r->fndata, "}\n"); +} + +void jsonrpc_return_success(struct jsonrpc_request *r, const char *result_fmt, + ...) { + va_list ap; + va_start(ap, result_fmt); + jsonrpc_return_successv(r, result_fmt, &ap); + va_end(ap); +} + +void jsonrpc_ctx_process(struct jsonrpc_ctx *ctx, const char *buf, int len, + mjson_print_fn_t fn, void *fndata, void *ud) { + const char *result = NULL, *error = NULL; + int result_sz = 0, error_sz = 0; + struct jsonrpc_method *m = NULL; + struct jsonrpc_request r = {ctx, buf, len, 0, 0, 0, 0, 0, 0, fn, fndata, ud}; + + // Is is a response frame? + mjson_find(buf, len, "$.result", &result, &result_sz); + if (result == NULL) mjson_find(buf, len, "$.error", &error, &error_sz); + if (result_sz > 0 || error_sz > 0) { + if (ctx->response_cb) ctx->response_cb(buf, len, ctx->response_cb_data); + return; + } + + // Method must exist and must be a string + if (mjson_find(buf, len, "$.method", &r.method, &r.method_len) != + MJSON_TOK_STRING) { + mjson_printf(fn, fndata, "{\"error\":{\"code\":-32700,\"message\":%.*Q}}\n", + len, buf); + return; + } + + // id and params are optional + mjson_find(buf, len, "$.id", &r.id, &r.id_len); + mjson_find(buf, len, "$.params", &r.params, &r.params_len); + + for (m = ctx->methods; m != NULL; m = m->next) { + if (mjson_globmatch(m->method, m->method_sz, r.method + 1, + r.method_len - 2) > 0) { + if (r.params == NULL) r.params = ""; + m->cb(&r); + break; + } + } + if (m == NULL) { + jsonrpc_return_error(&r, JSONRPC_ERROR_NOT_FOUND, "method not found", NULL); + } +} + +static int jsonrpc_print_methods(mjson_print_fn_t fn, void *fndata, + va_list *ap) { + struct jsonrpc_ctx *ctx = va_arg(*ap, struct jsonrpc_ctx *); + struct jsonrpc_method *m; + int len = 0; + for (m = ctx->methods; m != NULL; m = m->next) { + if (m != ctx->methods) len += mjson_print_buf(fn, fndata, ",", 1); + len += mjson_print_str(fn, fndata, m->method, (int) strlen(m->method)); + } + return len; +} + +void jsonrpc_list(struct jsonrpc_request *r) { + jsonrpc_return_success(r, "[%M]", jsonrpc_print_methods, r->ctx); +} + +void jsonrpc_ctx_init(struct jsonrpc_ctx *ctx, mjson_print_fn_t response_cb, + void *response_cb_data) { + ctx->methods = NULL; + ctx->response_cb = response_cb; + ctx->response_cb_data = response_cb_data; +} + +void jsonrpc_init(mjson_print_fn_t response_cb, void *userdata) { + struct jsonrpc_ctx *ctx = &jsonrpc_default_context; + jsonrpc_ctx_init(ctx, response_cb, userdata); + jsonrpc_ctx_export(ctx, MJSON_RPC_LIST_NAME, jsonrpc_list); +} +#endif // MJSON_ENABLE_RPC diff --git a/examples/huge-response/mjson.h b/examples/huge-response/mjson.h new file mode 100644 index 00000000..7db4b9f7 --- /dev/null +++ b/examples/huge-response/mjson.h @@ -0,0 +1,204 @@ +// Copyright (c) 2018-2020 Cesanta Software Limited +// All rights reserved +// +// Permission is hereby granted, free of charge, to any person obtaining a copy +// of this software and associated documentation files (the "Software"), to deal +// in the Software without restriction, including without limitation the rights +// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell +// copies of the Software, and to permit persons to whom the Software is +// furnished to do so, subject to the following conditions: +// +// The above copyright notice and this permission notice shall be included in +// all copies or substantial portions of the Software. +// +// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR +// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, +// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE +// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER +// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, +// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE +// SOFTWARE. + +#ifndef MJSON_H +#define MJSON_H + +#include +#include +#include + +#ifndef MJSON_ENABLE_PRINT +#define MJSON_ENABLE_PRINT 1 +#endif + +#ifndef MJSON_ENABLE_RPC +#define MJSON_ENABLE_RPC 1 +#endif + +#ifndef MJSON_ENABLE_BASE64 +#define MJSON_ENABLE_BASE64 1 +#endif + +#ifndef MJSON_ENABLE_MERGE +#define MJSON_ENABLE_MERGE 1 +#endif + +#ifndef MJSON_ENABLE_PRETTY +#define MJSON_ENABLE_PRETTY 1 +#endif + +#ifndef MJSON_ENABLE_NEXT +#define MJSON_ENABLE_NEXT 1 +#endif + +#ifndef MJSON_RPC_LIST_NAME +#define MJSON_RPC_LIST_NAME "rpc.list" +#endif + +#ifndef MJSON_DYNBUF_CHUNK +#define MJSON_DYNBUF_CHUNK 256 // Allocation granularity for print_dynamic_buf +#endif + +#ifdef __cplusplus +extern "C" { +#endif + +#define MJSON_ERROR_INVALID_INPUT (-1) +#define MJSON_ERROR_TOO_DEEP (-2) +#define MJSON_TOK_INVALID 0 +#define MJSON_TOK_KEY 1 +#define MJSON_TOK_STRING 11 +#define MJSON_TOK_NUMBER 12 +#define MJSON_TOK_TRUE 13 +#define MJSON_TOK_FALSE 14 +#define MJSON_TOK_NULL 15 +#define MJSON_TOK_ARRAY 91 +#define MJSON_TOK_OBJECT 123 +#define MJSON_TOK_IS_VALUE(t) ((t) > 10 && (t) < 20) + +typedef int (*mjson_cb_t)(int ev, const char *s, int off, int len, void *ud); + +#ifndef MJSON_MAX_DEPTH +#define MJSON_MAX_DEPTH 20 +#endif + +int mjson(const char *s, int len, mjson_cb_t cb, void *ud); +int mjson_find(const char *s, int len, const char *jp, const char **, int *); +int mjson_get_number(const char *s, int len, const char *path, double *v); +int mjson_get_bool(const char *s, int len, const char *path, int *v); +int mjson_get_string(const char *s, int len, const char *path, char *to, int n); +int mjson_get_hex(const char *s, int len, const char *path, char *to, int n); + +#if MJSON_ENABLE_NEXT +int mjson_next(const char *s, int n, int off, int *koff, int *klen, int *voff, + int *vlen, int *vtype); +#endif + +#if MJSON_ENABLE_BASE64 +int mjson_get_base64(const char *s, int len, const char *path, char *to, int n); +int mjson_base64_dec(const char *src, int n, char *dst, int dlen); +#endif + +#if MJSON_ENABLE_PRINT +typedef int (*mjson_print_fn_t)(const char *buf, int len, void *userdata); +typedef int (*mjson_vprint_fn_t)(mjson_print_fn_t, void *, va_list *); + +struct mjson_fixedbuf { + char *ptr; + int size, len; +}; + +int mjson_printf(mjson_print_fn_t, void *, const char *fmt, ...); +int mjson_vprintf(mjson_print_fn_t, void *, const char *fmt, va_list *ap); +int mjson_print_str(mjson_print_fn_t, void *, const char *s, int len); +int mjson_print_int(mjson_print_fn_t, void *, int value, int is_signed); +int mjson_print_long(mjson_print_fn_t, void *, long value, int is_signed); +int mjson_print_buf(mjson_print_fn_t fn, void *, const char *buf, int len); +int mjson_print_dbl(mjson_print_fn_t fn, void *, double, int width); + +int mjson_print_null(const char *ptr, int len, void *userdata); +int mjson_print_fixed_buf(const char *ptr, int len, void *userdata); +int mjson_print_dynamic_buf(const char *ptr, int len, void *userdata); + +int mjson_snprintf(char *buf, size_t len, const char *fmt, ...); +char *mjson_aprintf(const char *fmt, ...); + +#if MJSON_ENABLE_PRETTY +int mjson_pretty(const char *, int, const char *, mjson_print_fn_t, void *); +#endif + +#if MJSON_ENABLE_MERGE +int mjson_merge(const char *, int, const char *, int, mjson_print_fn_t, void *); +#endif + +#endif // MJSON_ENABLE_PRINT + +#if MJSON_ENABLE_RPC + +void jsonrpc_init(mjson_print_fn_t, void *userdata); +int mjson_globmatch(const char *s1, int n1, const char *s2, int n2); + +struct jsonrpc_request { + struct jsonrpc_ctx *ctx; + const char *frame; // Points to the whole frame + int frame_len; // Frame length + const char *params; // Points to the "params" in the request frame + int params_len; // Length of the "params" + const char *id; // Points to the "id" in the request frame + int id_len; // Length of the "id" + const char *method; // Points to the "method" in the request frame + int method_len; // Length of the "method" + mjson_print_fn_t fn; // Printer function + void *fndata; // Printer function data + void *userdata; // Callback's user data as specified at export time +}; + +struct jsonrpc_method { + const char *method; + int method_sz; + void (*cb)(struct jsonrpc_request *); + struct jsonrpc_method *next; +}; + +// Main RPC context, stores current request information and a list of +// exported RPC methods. +struct jsonrpc_ctx { + struct jsonrpc_method *methods; + mjson_print_fn_t response_cb; + void *response_cb_data; +}; + +// Registers function fn under the given name within the given RPC context +#define jsonrpc_ctx_export(ctx, name, fn) \ + do { \ + static struct jsonrpc_method m = {(name), sizeof(name) - 1, (fn), 0}; \ + m.next = (ctx)->methods; \ + (ctx)->methods = &m; \ + } while (0) + +void jsonrpc_ctx_init(struct jsonrpc_ctx *ctx, mjson_print_fn_t, void *); +void jsonrpc_return_error(struct jsonrpc_request *r, int code, + const char *message, const char *data_fmt, ...); +void jsonrpc_return_success(struct jsonrpc_request *r, const char *result_fmt, + ...); +void jsonrpc_ctx_process(struct jsonrpc_ctx *ctx, const char *req, int req_sz, + mjson_print_fn_t fn, void *fndata, void *userdata); + +extern struct jsonrpc_ctx jsonrpc_default_context; +extern void jsonrpc_list(struct jsonrpc_request *r); + +#define jsonrpc_export(name, fn) \ + jsonrpc_ctx_export(&jsonrpc_default_context, (name), (fn)) + +#define jsonrpc_process(buf, len, fn, fnd, ud) \ + jsonrpc_ctx_process(&jsonrpc_default_context, (buf), (len), (fn), (fnd), (ud)) + +#define JSONRPC_ERROR_INVALID -32700 /* Invalid JSON was received */ +#define JSONRPC_ERROR_NOT_FOUND -32601 /* The method does not exist */ +#define JSONRPC_ERROR_BAD_PARAMS -32602 /* Invalid params passed */ +#define JSONRPC_ERROR_INTERNAL -32603 /* Internal JSON-RPC error */ + +#endif // MJSON_ENABLE_RPC +#ifdef __cplusplus +} +#endif +#endif // MJSON_H diff --git a/examples/huge-response/web_root/index.html b/examples/huge-response/web_root/index.html new file mode 100644 index 00000000..0c92becc --- /dev/null +++ b/examples/huge-response/web_root/index.html @@ -0,0 +1,59 @@ + + + + example + + + + + + +
+
+ On devices with limited RAM, it is important to limit the response size + of API calls. This example demonstrates how to fetch a large + data in smaller chunks, and guarantee its integrity. + Data gets returned in a series of request/response transactions, + where each response is small enough to fit into available device RAM. +

+ Data integrity is implemented by versioning. + The idea is that the first response includes the current "version" of the + data, and that version is passed to all subsequent requests. + If data version changes in the middle of the request series, + client fails with 'wrong version' error. +
+ +
+
+ + +