diff options
| -rw-r--r-- | Makefile | 11 | ||||
| -rw-r--r-- | core/module-text.c | 29 | ||||
| -rw-r--r-- | core/test-module.c | 36 | ||||
| -rw-r--r-- | serve/message-json.c | 30 | ||||
| -rw-r--r-- | serve/test-message-json.c | 68 |
5 files changed, 172 insertions, 2 deletions
@@ -16,7 +16,8 @@ BUILD ?= build # cli/ command-line hosts. # libpure.a is the app model with the tree store: what a host embeds (Vega's # surfaces link it). prototypes/ keeps the earlier document runtime (000-077). -# Unit tests sit by their part (core/test-module.c, store/test-tree-store.c); +# Unit tests sit by their part (core/test-module.c, store/test-tree-store.c, +# serve/test-message-json.c); # tests/check.py checks the hosts end to end. INCLUDES = -Icore MODEL = core/module.c core/module-list.c core/module-save.c core/module-text.c core/module-store.c core/flow.c @@ -59,6 +60,11 @@ $(BUILD)/test-module: core/test-module.c $(MODEL) $(STORE) $(HEADERS) @mkdir -p $(BUILD) $(CC) $(CPPFLAGS) $(CFLAGS) $(INCLUDES) -DPURE_STORE_TEST core/test-module.c $(MODEL) $(STORE) $(LDFLAGS) -pthread -lm $(LDLIBS) -o $@ +$(BUILD)/test-message-json: serve/test-message-json.c serve/message-json.c $(BUILD)/libpure.a $(HEADERS) + @mkdir -p $(BUILD) + $(CC) $(CPPFLAGS) $(CFLAGS) $(INCLUDES) -Iserve serve/test-message-json.c serve/message-json.c $(BUILD)/libpure.a \ + $(LDFLAGS) -lm $(LDLIBS) -o $@ + $(BUILD)/test-tree-store: store/test-tree-store.c $(STORE) $(HEADERS) @mkdir -p $(BUILD) $(CC) $(CPPFLAGS) $(CFLAGS) $(INCLUDES) -DPURE_STORE_TEST store/test-tree-store.c $(STORE) $(LDFLAGS) $(LDLIBS) -o $@ @@ -66,9 +72,10 @@ $(BUILD)/test-tree-store: store/test-tree-store.c $(STORE) $(HEADERS) # The HTTP host's checks build their apps with aup (the sibling checkout) and # compare documents with the earlier document server. AUP ?= ../aup -check: all $(BUILD)/test-module $(BUILD)/test-tree-store +check: all $(BUILD)/test-module $(BUILD)/test-tree-store $(BUILD)/test-message-json $(BUILD)/test-tree-store $(BUILD)/test-module + $(BUILD)/test-message-json $(MAKE) -C $(AUP) build/aup $(MAKE) -C prototypes/connections BUILD=build/tree STORE=store-tree.c build/tree/pure-connections python3 tests/check.py --aup $(AUP)/build/aup --aup-root $(AUP) diff --git a/core/module-text.c b/core/module-text.c index 68c03b0..4ce1769 100644 --- a/core/module-text.c +++ b/core/module-text.c @@ -72,6 +72,35 @@ size_t pure_format_number(double value, char out[32]) { out[length] = 0; return length; } + /* The fewest decimals k whose digits, the value * 10^k rounded to the + * nearest integer m, read back as the value: %g's digits. m and 10^k are + * exact (m < 2^53, k <= 22), so m / 10^k is the correctly rounded value of + * those digits, as reading them is; the product's rounding error (fma) + * tells the nearest m, and a half between two goes to %g. Else, and for + * what %g would write with an exponent, the fewest %g digits that do. */ + static const double tens[] = {1e0, 1e1, 1e2, 1e3, 1e4, 1e5, 1e6, 1e7, 1e8, 1e9, 1e10, 1e11, + 1e12, 1e13, 1e14, 1e15, 1e16}; + double magnitude = fabs(value); + if (magnitude >= 1e-4 && magnitude < 1e15) + for (int k = 1; k <= 16; ++k) { + double scaled = magnitude * tens[k]; + if (scaled >= 9007199254740992.0) break; + uint64_t m = (uint64_t)scaled; + double beyond = (scaled - (double)m) + fma(magnitude, tens[k], -scaled); + if (beyond == 0.5) break; + m += beyond > 0.5; + if ((double)m / tens[k] != magnitude) continue; + char digits[24]; + size_t count = 0, length = 0; + do { digits[count++] = (char)('0' + m % 10); m /= 10; } while (m); + while (count <= (size_t)k) digits[count++] = '0'; /* a leading zero before the point */ + if (value < 0) out[length++] = '-'; + while (count > (size_t)k) out[length++] = digits[--count]; + out[length++] = '.'; + while (count) out[length++] = digits[--count]; + out[length] = 0; + return length; + } for (int precision = 1; precision <= 17; ++precision) { snprintf(out, 32, "%.*g", precision, value); if (strtod(out, NULL) == value) break; diff --git a/core/test-module.c b/core/test-module.c index d5b7eee..8ca031c 100644 --- a/core/test-module.c +++ b/core/test-module.c @@ -3987,7 +3987,43 @@ static void timers(void) { CHECK(load(bad, &module_b) == PURE_INVALID && strstr(error, "view with an effect")); } +/* A number is written with the fewest digits that read back as it, the + * digits %g gives (with its exponent's leading zeros dropped): the same + * text as that search over precisions, for values of every kind. */ +static void number_texts(void) { + uint32_t seed = 0x6e756d73u; + size_t checked = 0; + for (unsigned i = 0; i < 300000; ++i) { + double value; + uint64_t bits = (uint64_t)next_random(&seed) << 32 | next_random(&seed); + switch (i % 5) { + case 0: value = (double)((int64_t)(bits % 2000001) - 1000000) / 100.0; break; /* money */ + case 1: value = (double)(bits % 20000001) / pow(10, (double)(bits >> 40 & 7)); break; /* decimals */ + case 2: memcpy(&value, &bits, sizeof(value)); if (!isfinite(value)) value = 0.75; break; + case 3: value = (double)(bits % 100000) / 7.0; break; + default: value = ldexp((double)(bits >> 11), (int)(bits % 80) - 60); break; + } + char got[32], want[32]; + pure_format_number(value, got); + if (value == 0) strcpy(want, "0"); + else if (value == floor(value) && fabs(value) < 1e15) snprintf(want, sizeof(want), "%.0f", value); + else { + for (int precision = 1; precision <= 17; ++precision) { + snprintf(want, sizeof(want), "%.*g", precision, value); + if (strtod(want, NULL) == value) break; + } + char *exponent = strchr(want, 'e'); + if (exponent) + while (exponent[2] == '0' && exponent[3]) memmove(exponent + 2, exponent + 3, strlen(exponent + 2)); + } + CHECK(!strcmp(got, want) && strtod(got, NULL) == value); + ++checked; + } + printf("{\"number_texts\":%zu}\n", checked); +} + int main(void) { + number_texts(); behaviour(); faults(); rejections(); diff --git a/serve/message-json.c b/serve/message-json.c index 8c288ce..643cc28 100644 --- a/serve/message-json.c +++ b/serve/message-json.c @@ -46,6 +46,36 @@ static size_t json_number(const unsigned char *p, size_t size, bool *integer) { static bool json_double(const unsigned char *text, size_t size, double *value) { bool integer; if (!size || json_number(text, size, &integer) != size || size > 40) return false; + /* Digits m < 2^53 and a power of ten 10^e, |e| <= 22, are exact, so one + * multiplication or division rounds m * 10^e correctly (Clinger's fast + * path); other numbers go to strtod. */ + static const double tens[] = {1e0, 1e1, 1e2, 1e3, 1e4, 1e5, 1e6, 1e7, 1e8, 1e9, 1e10, 1e11, + 1e12, 1e13, 1e14, 1e15, 1e16, 1e17, 1e18, 1e19, 1e20, 1e21, 1e22}; + const unsigned char *p = text, *end = text + size; + bool negative = *p == '-', exact = true; + uint64_t m = 0; + int exponent = 0; + p += negative; + for (; p < end && *p >= '0' && *p <= '9'; ++p) { + exact = exact && m < UINT64_C(900719925474099); + m = m * 10 + (uint64_t)(*p - '0'); + } + if (p < end && *p == '.') + for (++p; p < end && *p >= '0' && *p <= '9'; ++p, --exponent) { + exact = exact && m < UINT64_C(900719925474099); + m = m * 10 + (uint64_t)(*p - '0'); + } + if (p < end) { /* an exponent */ + bool below = *++p == '-'; + int e = 0; + for (p += *p == '-' || *p == '+'; p < end; ++p) e = e < 1000 ? e * 10 + (*p - '0') : e; + exponent += below ? -e : e; + } + if (exact && exponent >= -22 && exponent <= 22) { + double v = exponent < 0 ? (double)m / tens[-exponent] : (double)m * tens[exponent]; + *value = negative ? -v : v; + return true; + } char digits[48]; memcpy(digits, text, size); digits[size] = 0; diff --git a/serve/test-message-json.c b/serve/test-message-json.c new file mode 100644 index 0000000..618a363 --- /dev/null +++ b/serve/test-message-json.c @@ -0,0 +1,68 @@ +/* JSON numbers are read as strtod reads them, bit for bit: in the forms a + * client writes (a program's shortest digits, fixed decimals, exponents), at + * the edges of the exact path (2^53, 10^22) and past them, and refused when + * not finite or not JSON. */ +#include "message-json.h" +#include <math.h> +#include <stdint.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> + +#define CHECK(x) do { if (!(x)) { fprintf(stderr, "%s:%d: %s\n", __FILE__, __LINE__, #x); exit(1); } } while (0) + +static uint64_t next_random(uint64_t *state) { + uint64_t x = *state; + x ^= x << 13, x ^= x >> 7, x ^= x << 17; + return *state = x; +} + +/* The text read as a number field: true with its value, or false. */ +static bool read_number(const char *text, double *value) { + static const PureField number = {.type = PURE_FIELD_NUMBER}; + unsigned char prefix[8]; + if (!pure_json_fixed(&number, (const unsigned char *)text, strlen(text), prefix)) return false; + memcpy(value, prefix, sizeof(*value)); + return true; +} + +static void same_as_strtod(const char *text) { + double got, want = strtod(text, NULL); + CHECK(read_number(text, &got) && !memcmp(&got, &want, sizeof(got))); +} + +int main(void) { + static const char *const edges[] = { + "0", "-0", "0.0", "-0.0", "1", "0.1", "0.2", "0.30000000000000004", "123456.789", "1e22", "1e23", "1E-22", + "1e-23", "9007199254740991", "9007199254740992", "9007199254740993", "900719925474099.3", "12345678901234567890", + "0.000000000000000000000001", "1.7976931348623157e308", "4.9406564584124654e-324", "2.2250738585072014e-308", + "-123.456e-7", "5e+0", "0.5e1", "1234567890.0987654321"}; + for (size_t i = 0; i < sizeof(edges) / sizeof(*edges); ++i) same_as_strtod(edges[i]); + static const char *const refused[] = {"1e309", "-1e400", "01", "1.", ".5", "+1", "1e", "--1", "0x10", "1.5e+", "NaN"}; + for (size_t i = 0; i < sizeof(refused) / sizeof(*refused); ++i) { + double value; + CHECK(!read_number(refused[i], &value)); + } + uint64_t seed = 0x6a736f6eu; + size_t read = 0; + for (unsigned i = 0; i < 400000; ++i) { + uint64_t bits = next_random(&seed); + double value; + switch (i % 4) { + case 0: value = (double)(int64_t)(bits % 2000001 - 1000000) / 100.0; break; + case 1: value = (double)(bits % 100000000) / pow(10, (double)(bits >> 50 & 15)); break; + case 2: memcpy(&value, &bits, sizeof(value)); if (!isfinite(value)) value = -2.5; break; + default: value = ldexp((double)(bits >> 11), (int)(bits % 120) - 90); break; + } + char text[64]; + snprintf(text, sizeof(text), "%.17g", value); + same_as_strtod(text); + snprintf(text, sizeof(text), "%.*f", (int)(bits >> 56) % 12, value); + if (strlen(text) < 40) same_as_strtod(text); + snprintf(text, sizeof(text), "%.*e", (int)(bits >> 58) % 17, value); + same_as_strtod(text); + read += 3; + } + printf("{\"json_numbers\":%zu}\n", read); + return 0; +} |