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fabiosvmfabiosvm
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added geohash extension
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5 files changed

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‎extensions/CMakeLists.txt‎

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@@ -90,6 +90,10 @@ add_library(uuid_mod SHARED
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uuid.c
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deps/uuid4.c)
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add_library(geohash_mod SHARED
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geohash.c
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deps/geohash.c)
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target_link_libraries(sqlite_mod ${STATIC_LIB_TARGET})
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target_link_libraries(curl_mod ${STATIC_LIB_TARGET})
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target_link_libraries(redis_mod ${STATIC_LIB_TARGET})
@@ -102,6 +106,7 @@ target_link_libraries(leveldb_mod ${STATIC_LIB_TARGET})
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target_link_libraries(crypto_mod ${STATIC_LIB_TARGET})
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target_link_libraries(regex_mod ${STATIC_LIB_TARGET})
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target_link_libraries(uuid_mod ${STATIC_LIB_TARGET})
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target_link_libraries(geohash_mod ${STATIC_LIB_TARGET})
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set_target_properties(sqlite_mod PROPERTIES PREFIX "")
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set_target_properties(curl_mod PROPERTIES PREFIX "")
@@ -115,6 +120,7 @@ set_target_properties(leveldb_mod PROPERTIES PREFIX "")
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set_target_properties(crypto_mod PROPERTIES PREFIX "")
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set_target_properties(regex_mod PROPERTIES PREFIX "")
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set_target_properties(uuid_mod PROPERTIES PREFIX "")
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set_target_properties(geohash_mod PROPERTIES PREFIX "")
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if(MSVC)
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target_link_libraries(sqlite_mod PRIVATE SQLite::SQLite3)

‎extensions/deps/geohash.c‎

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/* This is a public domain geohash implementation written by WEI Zhicheng. */
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#include <math.h>
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#include <float.h>
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#include <string.h>
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#include "geohash.h"
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/* BASE 32 encode table */
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static char base32en[] = {
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'0', '1', '2', '3', '4', '5', '6', '7',
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'8', '9', 'b', 'c', 'd', 'e', 'f', 'g',
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'h', 'j', 'k', 'm', 'n', 'p', 'q', 'r',
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's', 't', 'u', 'v', 'w', 'x', 'y', 'z'
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};
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#define BASE32DE_FIRST '0'
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#define BASE32DE_LAST 'z'
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/* ASCII order for BASE 32 decode,from '0' to 'z', -1 in unused character */
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static signed char base32de[] = {
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0, 1, 2, 3, 4, 5, 6, 7, 8, 9,
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-1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
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-1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
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-1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
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-1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
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10, 11, 12, 13, 14, 15, 16, -1, 17, 18,
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-1, 19, 20, -1, 21, 22, 23, 24, 25, 26,
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27, 28, 29, 30, 31
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};
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#define PRECISION .00000000001 /* XXX not validated */
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static int
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max(int x, int y)
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{
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if (x < y)
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return y;
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return x;
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}
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static double
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pround(double x, int precision)
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{
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double div = pow(10, precision);
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return round(x * div) / div;
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}
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/* Quick and Dirty Floating-Point to Fractional Precision */
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static double
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fprec(double x)
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{
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int i;
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double int_part, frac_part;
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frac_part = modf(x, &int_part);
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/* check fractional is really close 0.0 or 1.0 */
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for (i = 0; fabs(frac_part - 0.0) > FLT_EPSILON &&
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fabs(frac_part - 1.0) > FLT_EPSILON; i++) {
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frac_part *= 10;
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frac_part = modf(frac_part, &int_part);
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}
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return pow(10, -i);
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}
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int
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geohash_encode(double latitude, double longitude, char *hash, size_t len)
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{
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double lat[] = {-90.0, 90.0};
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double lon[] = {-180.0, 180.0};
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double mid;
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double precision;
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char mask[] = {16, 8, 4, 2, 1};
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size_t i, n;
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int idx;
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int even = 0;
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int right;
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/* check input latitude/longitude is ok or invalid */
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if (latitude < lat[0] || latitude > lat[1] ||
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longitude < lon[0] || longitude > lon[1])
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return GEOHASH_INVALID;
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precision = fmin(fprec(latitude), fprec(longitude));
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precision = fmax(PRECISION, precision);
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/* save the last space for '\0' when len is not enough */
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len -= 1;
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for (i = 0; i < len; i++) {
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/* break when precision is enough for input latitude/longitude */
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if ((lat[1] - lat[0]) / 2.0 < precision &&
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(lon[1] - lon[0]) / 2.0 < precision)
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break;
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for (n = idx = 0; n <= 4; n++) {
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if ((even = !even)) {
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mid = (lon[0] + lon[1]) / 2.0;
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right = (longitude > mid);
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if (right)
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idx |= mask[n];
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lon[!right] = mid;
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} else {
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mid = (lat[0] + lat[1]) / 2.0;
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right = (latitude > mid);
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if (right)
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idx |= mask[n];
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lat[!right] = mid;
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}
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}
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hash[i] = base32en[idx];
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}
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hash[i] = 0;
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return GEOHASH_OK;
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}
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int
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geohash_decode(char *hash, double *latitude, double *longitude)
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{
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size_t len = strlen(hash);
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double lat[] = {-90.0, 90.0};
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double lon[] = {-180.0, 180.0};
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double mid;
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double lat_err, lon_err;
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char mask[] = {16, 8, 4, 2, 1};
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size_t i, n;
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int idx = 0;
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int even = 0;
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int right;
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for (i = 0; i < len; i++) {
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if (hash[i] < BASE32DE_FIRST || hash[i] > BASE32DE_LAST ||
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(idx = base32de[hash[i] - BASE32DE_FIRST]) == -1)
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return GEOHASH_INVALID;
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for (n = 0; n <= 4; n++) {
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if ((even = !even)) {
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mid = (lon[0] + lon[1]) / 2.0;
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right = (idx & mask[n]);
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lon[!right] = mid;
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} else {
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mid = (lat[0] + lat[1]) / 2.0;
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right = (idx & mask[n]);
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lat[!right] = mid;
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}
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}
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}
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lat_err = (lat[1] - lat[0]) / 2.0;
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*latitude = pround((lat[0] + lat[1]) / 2.0,
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max(1, (int)round(-log10(lat_err))) - 1);
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lon_err = (lon[1] - lon[0]) / 2.0;
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*longitude = pround((lon[0] + lon[1]) / 2.0,
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max(1, (int)round(-log10(lon_err))) - 1);
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return GEOHASH_OK;
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}

‎extensions/deps/geohash.h‎

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/* This is a public domain geohash implementation written by WEI Zhicheng. */
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#ifndef __GEOHASH_H__
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#define __GEOHASH_H__
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#include <stdlib.h>
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enum {GEOHASH_OK = 0, GEOHASH_INVALID};
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int
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geohash_encode(double latitude, double longitude, char *hash, size_t len);
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int
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geohash_decode(char *hash, double *latitude, double *longitude);
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#endif /* __GEOHASH_H__ */

‎extensions/geohash.c‎

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//
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// The Hook Programming Language
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// geohash.c
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//
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#include "geohash.h"
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#include "deps/geohash.h"
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static void encode_call(HkState *state, HkValue *args);
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static void decode_call(HkState *state, HkValue *args);
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static void encode_call(HkState *state, HkValue *args)
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{
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hk_state_check_argument_number(state, args, 1);
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hk_return_if_not_ok(state);
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hk_state_check_argument_number(state, args, 2);
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hk_return_if_not_ok(state);
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double lat = hk_as_number(args[1]);
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double lon = hk_as_number(args[2]);
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char buf[16] = {0};
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if (geohash_encode(lat, lon, buf, sizeof(buf)) != GEOHASH_OK)
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{
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hk_state_push_nil(state);
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return;
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}
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HkString *str = hk_string_from_chars(-1, buf);
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hk_state_push_string(state, str);
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if (!hk_state_is_ok(state))
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hk_string_free(str);
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}
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static void decode_call(HkState *state, HkValue *args)
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{
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hk_state_check_argument_string(state, args, 1);
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hk_return_if_not_ok(state);
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HkString *str = hk_as_string(args[1]);
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double lat = 0.0;
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double lon = 0.0;
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if (geohash_decode(str->chars, &lat, &lon) != GEOHASH_OK)
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{
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hk_state_push_nil(state);
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return;
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}
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HkArray *arr = hk_array_new_with_capacity(2);
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hk_array_inplace_add_element(arr, hk_number_value(lat));
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hk_array_inplace_add_element(arr, hk_number_value(lon));
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hk_state_push_array(state, arr);
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if (!hk_state_is_ok(state))
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hk_array_free(arr);
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}
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HK_LOAD_MODULE_HANDLER(geohash)
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{
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hk_state_push_string_from_chars(state, -1, "geohash");
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hk_return_if_not_ok(state);
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hk_state_push_string_from_chars(state, -1, "encode");
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hk_return_if_not_ok(state);
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hk_state_push_new_native(state, "encode", 2, encode_call);
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hk_return_if_not_ok(state);
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hk_state_push_string_from_chars(state, -1, "decode");
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hk_return_if_not_ok(state);
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hk_state_push_new_native(state, "decode", 1, decode_call);
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hk_return_if_not_ok(state);
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hk_state_construct(state, 2);
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}

‎extensions/geohash.h‎

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//
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// The Hook Programming Language
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// geohash.h
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//
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#ifndef GEOHASH_H
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#define GEOHASH_H
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#include <hook.h>
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HK_LOAD_MODULE_HANDLER(geohash);
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#endif // GEOHASH_H

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