/* * Copyright (c) 2014, Matt Stancliff . * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions are met: * * * Redistributions of source code must retain the above copyright notice, * this list of conditions and the following disclaimer. * * Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * Neither the name of Redis nor the names of its contributors may be used * to endorse or promote products derived from this software without * specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE * POSSIBILITY OF SUCH DAMAGE. */ #include "geo.h" #include "geohash_helper.h" /* Things exported from t_zset.c only for geo.c, since it is the only other * part of Redis that requires close zset introspection. */ unsigned char *zzlFirstInRange(unsigned char *zl, zrangespec *range); int zslValueLteMax(double value, zrangespec *spec); /* ==================================================================== * This file implements the following commands: * * - geoadd - add coordinates for value to geoset * - georadius - search radius by coordinates in geoset * - georadiusbymember - search radius based on geoset member position * - geoencode - encode coordinates to a geohash integer * - geodecode - decode geohash integer to representative coordinates * ==================================================================== */ /* ==================================================================== * geoArray implementation * ==================================================================== */ /* Create a new array of geoPoints. */ geoArray *geoArrayCreate(void) { geoArray *ga = zmalloc(sizeof(*ga)); /* It gets allocated on first geoArrayAppend() call. */ ga->array = NULL; ga->buckets = 0; ga->used = 0; return ga; } /* Add a new entry and return its pointer so that the caller can populate * it with data. */ geoPoint *geoArrayAppend(geoArray *ga) { if (ga->used == ga->buckets) { ga->buckets = (ga->buckets == 0) ? 8 : ga->buckets*2; ga->array = zrealloc(ga->array,sizeof(geoPoint)*ga->buckets); } geoPoint *gp = ga->array+ga->used; ga->used++; return gp; } /* Destroy a geoArray created with geoArrayCreate(). */ void geoArrayFree(geoArray *ga) { size_t i; for (i = 0; i < ga->used; i++) sdsfree(ga->array[i].member); zfree(ga->array); zfree(ga); } /* ==================================================================== * Helpers * ==================================================================== */ static inline int decodeGeohash(double bits, double *latlong) { GeoHashBits hash = { .bits = (uint64_t)bits, .step = GEO_STEP_MAX }; return geohashDecodeToLatLongWGS84(hash, latlong); } /* Input Argument Helper */ /* Take a pointer to the latitude arg then use the next arg for longitude */ static inline int extractLatLongOrReply(redisClient *c, robj **argv, double *latlong) { for (int i = 0; i < 2; i++) { if (getDoubleFromObjectOrReply(c, argv[i], latlong + i, NULL) != REDIS_OK) { return 0; } } return 1; } /* Input Argument Helper */ /* Decode lat/long from a zset member's score. * Returns non-zero on successful decoding. */ static int latLongFromMember(robj *zobj, robj *member, double *latlong) { double score = 0; if (zsetScore(zobj, member, &score) == REDIS_ERR) return 0; if (!decodeGeohash(score, latlong)) return 0; return 1; } /* Input Argument Helper */ static double extractDistanceOrReply(redisClient *c, robj **argv, double *conversion) { double distance; if (getDoubleFromObjectOrReply(c, argv[0], &distance, "need numeric radius") != REDIS_OK) { return -1; } double to_meters; sds units = argv[1]->ptr; if (!strcmp(units, "m") || !strncmp(units, "meter", 5)) { to_meters = 1; } else if (!strcmp(units, "ft") || !strncmp(units, "feet", 4)) { to_meters = 0.3048; } else if (!strcmp(units, "mi") || !strncmp(units, "mile", 4)) { to_meters = 1609.34; } else if (!strcmp(units, "km") || !strncmp(units, "kilometer", 9)) { to_meters = 1000; } else { addReplyError(c, "unsupported unit provided. please use meters (m), " "kilometers (km), miles (mi), or feet (ft)"); return -1; } if (conversion) *conversion = to_meters; return distance * to_meters; } /* The defailt addReplyDouble has too much accuracy. We use this * for returning location distances. "5.2145 meters away" is nicer * than "5.2144992818115 meters away." We provide 4 digits after the dot * so that the returned value is decently accurate even when the unit is * the kilometer. */ static inline void addReplyDoubleDistance(redisClient *c, double d) { char dbuf[128]; int dlen = snprintf(dbuf, sizeof(dbuf), "%.4f", d); addReplyBulkCBuffer(c, dbuf, dlen); } /* Helper function for geoGetPointsInRange(): given a sorted set score * representing a point, and another point (the center of our search) and * a radius, appends this entry as a geoPoint into the specified geoArray * only if the point is within the search area. * * returns REDIS_OK if the point is included, or REIDS_ERR if it is outside. */ int geoAppendIfWithinRadius(geoArray *ga, double lat, double lon, double radius, double score, sds member) { double distance, latlong[2]; if (!decodeGeohash(score,latlong)) return REDIS_ERR; /* Can't decode. */ /* Note that geohashGetDistanceIfInRadiusWGS84() takes arguments in * reverse order: longitude first, latitude later. */ if (!geohashGetDistanceIfInRadiusWGS84(lon,lat,latlong[1], latlong[0], radius, &distance)) { return REDIS_ERR; } /* Append the new element. */ geoPoint *gp = geoArrayAppend(ga); gp->latitude = latlong[0]; gp->longitude = latlong[1]; gp->dist = distance; gp->member = member; gp->score = score; return REDIS_OK; } /* Query a Redis sorted set to extract all the elements between 'min' and * 'max', appending them into the array of geoPoint structures 'gparray'. * The command returns the number of elements added to the array. * * Elements which are farest than 'radius' from the specified 'x' and 'y' * coordinates are not included. * * The ability of this function to append to an existing set of points is * important for good performances because querying by radius is performed * using multiple queries to the sorted set, that we later need to sort * via qsort. Similarly we need to be able to reject points outside the search * radius area ASAP in order to allocate and process more points than needed. */ int geoGetPointsInRange(robj *zobj, double min, double max, double lat, double lon, double radius, geoArray *ga) { /* minex 0 = include min in range; maxex 1 = exclude max in range */ /* That's: min <= val < max */ zrangespec range = { .min = min, .max = max, .minex = 0, .maxex = 1 }; size_t origincount = ga->used; sds member; if (zobj->encoding == REDIS_ENCODING_ZIPLIST) { unsigned char *zl = zobj->ptr; unsigned char *eptr, *sptr; unsigned char *vstr = NULL; unsigned int vlen = 0; long long vlong = 0; double score = 0; if ((eptr = zzlFirstInRange(zl, &range)) == NULL) { /* Nothing exists starting at our min. No results. */ return 0; } sptr = ziplistNext(zl, eptr); while (eptr) { score = zzlGetScore(sptr); /* If we fell out of range, break. */ if (!zslValueLteMax(score, &range)) break; /* We know the element exists. ziplistGet should always succeed */ ziplistGet(eptr, &vstr, &vlen, &vlong); member = (vstr == NULL) ? sdsfromlonglong(vlong) : sdsnewlen(vstr,vlen); if (geoAppendIfWithinRadius(ga,lat,lon,radius,score,member) == REDIS_ERR) sdsfree(member); zzlNext(zl, &eptr, &sptr); } } else if (zobj->encoding == REDIS_ENCODING_SKIPLIST) { zset *zs = zobj->ptr; zskiplist *zsl = zs->zsl; zskiplistNode *ln; if ((ln = zslFirstInRange(zsl, &range)) == NULL) { /* Nothing exists starting at our min. No results. */ return 0; } while (ln) { robj *o = ln->obj; /* Abort when the node is no longer in range. */ if (!zslValueLteMax(ln->score, &range)) break; member = (o->encoding == REDIS_ENCODING_INT) ? sdsfromlonglong((long)o->ptr) : sdsdup(o->ptr); if (geoAppendIfWithinRadius(ga,lat,lon,radius,ln->score,member) == REDIS_ERR) sdsfree(member); ln = ln->level[0].forward; } } return ga->used - origincount; } /* Obtain all members between the min/max of this geohash bounding box. * Populate a geoArray of GeoPoints by calling geoGetPointsInRange(). * Return the number of points added to the array. */ int membersOfGeoHashBox(robj *zobj, GeoHashBits hash, geoArray *ga, double lat, double lon, double radius) { GeoHashFix52Bits min, max; min = geohashAlign52Bits(hash); hash.bits++; max = geohashAlign52Bits(hash); return geoGetPointsInRange(zobj, min, max, lat, lon, radius, ga); } /* Search all eight neighbors + self geohash box */ int membersOfAllNeighbors(robj *zobj, GeoHashRadius n, double lat, double lon, double radius, geoArray *ga) { GeoHashBits neighbors[9]; unsigned int i, count = 0; neighbors[0] = n.hash; neighbors[1] = n.neighbors.north; neighbors[2] = n.neighbors.south; neighbors[3] = n.neighbors.east; neighbors[4] = n.neighbors.west; neighbors[5] = n.neighbors.north_east; neighbors[6] = n.neighbors.north_west; neighbors[7] = n.neighbors.south_east; neighbors[8] = n.neighbors.south_west; /* For each neighbor (*and* our own hashbox), get all the matching * members and add them to the potential result list. */ for (i = 0; i < sizeof(neighbors) / sizeof(*neighbors); i++) { if (HASHISZERO(neighbors[i])) continue; count += membersOfGeoHashBox(zobj, neighbors[i], ga, lat, lon, radius); } return count; } /* Sort comparators for qsort() */ static int sort_gp_asc(const void *a, const void *b) { const struct geoPoint *gpa = a, *gpb = b; /* We can't do adist - bdist because they are doubles and * the comparator returns an int. */ if (gpa->dist > gpb->dist) return 1; else if (gpa->dist == gpb->dist) return 0; else return -1; } static int sort_gp_desc(const void *a, const void *b) { return -sort_gp_asc(a, b); } /* ==================================================================== * Commands * ==================================================================== */ void geoAddCommand(redisClient *c) { /* args 0-4: [cmd, key, lat, lng, val]; optional 5-6: [radius, units] * - OR - * args 0-N: [cmd, key, lat, lng, val, lat2, lng2, val2, ...] */ robj *cmd = c->argv[0]; robj *key = c->argv[1]; /* Prepare for the three different forms of the add command. */ double radius_meters = 0; if (c->argc == 7) { if ((radius_meters = extractDistanceOrReply(c, c->argv + 5, NULL)) < 0) { return; } } else if (c->argc == 6) { addReplyError(c, "must provide units when asking for radius encode"); return; } else if ((c->argc - 2) % 3 != 0) { /* Need an odd number of arguments if we got this far... */ addReplyError(c, "format is: geoadd [key] [lat1] [long1] [member1] " "[lat2] [long2] [member2] ... "); return; } redisClient *client = c; int elements = (c->argc - 2) / 3; /* elements will always be correct size (integer math floors for us if we * have 6 or 7 total arguments) */ if (elements > 1) { /* We should probably use a static client and not create/free it * for every multi-add */ client = createClient(-1); /* fake client for multi-zadd */ /* Tell fake client to use the same DB as our calling client. */ selectDb(client, c->db->id); } /* Capture all lat/long components up front so if we encounter an error we * return before making any changes to the database. */ double latlong[elements * 2]; for (int i = 0; i < elements; i++) { if (!extractLatLongOrReply(c, (c->argv + 2) + (i * 3), latlong + (i * 2))) return; } /* Add all (lat, long, value) triples to the requested zset */ for (int i = 0; i < elements; i++) { uint8_t step = geohashEstimateStepsByRadius(radius_meters); #ifdef DEBUG printf("Adding with step size: %d\n", step); #endif GeoHashBits hash; int ll_offset = i * 2; double latitude = latlong[ll_offset]; double longitude = latlong[ll_offset + 1]; geohashEncodeWGS84(latitude, longitude, step, &hash); GeoHashFix52Bits bits = geohashAlign52Bits(hash); robj *score = createObject(REDIS_STRING, sdsfromlonglong(bits)); robj *val = c->argv[2 + i * 3 + 2]; /* (base args) + (offset for this triple) + (offset of value arg) */ rewriteClientCommandVector(client, 4, cmd, key, score, val); decrRefCount(score); zaddCommand(client); } /* If we used a fake client, return a real reply then free fake client. */ if (client != c) { addReplyLongLong(c, elements); freeClient(client); } } #define SORT_NONE 0 #define SORT_ASC 1 #define SORT_DESC 2 #define RADIUS_COORDS 1 #define RADIUS_MEMBER 2 static void geoRadiusGeneric(redisClient *c, int type) { /* type == cords: [cmd, key, lat, long, radius, units, [optionals]] * type == member: [cmd, key, member, radius, units, [optionals]] */ robj *key = c->argv[1]; /* Look up the requested zset */ robj *zobj = NULL; if ((zobj = lookupKeyReadOrReply(c, key, shared.emptymultibulk)) == NULL || checkType(c, zobj, REDIS_ZSET)) { return; } /* Find lat/long to use for radius search based on inquiry type */ int base_args; double latlong[2] = { 0 }; if (type == RADIUS_COORDS) { base_args = 6; if (!extractLatLongOrReply(c, c->argv + 2, latlong)) return; } else if (type == RADIUS_MEMBER) { base_args = 5; robj *member = c->argv[2]; if (!latLongFromMember(zobj, member, latlong)) { addReplyError(c, "could not decode requested zset member"); return; } } else { addReplyError(c, "unknown georadius search type"); return; } /* Extract radius and units from arguments */ double radius_meters = 0, conversion = 1; if ((radius_meters = extractDistanceOrReply(c, c->argv + base_args - 2, &conversion)) < 0) { return; } /* Discover and populate all optional parameters. */ int withdist = 0, withhash = 0, withcoords = 0, noproperties = 0; int sort = SORT_NONE; if (c->argc > base_args) { int remaining = c->argc - base_args; for (int i = 0; i < remaining; i++) { char *arg = c->argv[base_args + i]->ptr; if (!strncasecmp(arg, "withdist", 8)) withdist = 1; else if (!strcasecmp(arg, "withhash")) withhash = 1; else if (!strncasecmp(arg, "withcoord", 9)) withcoords = 1; else if (!strncasecmp(arg, "noprop", 6) || !strncasecmp(arg, "withoutprop", 11)) noproperties = 1; else if (!strncasecmp(arg, "asc", 3) || !strncasecmp(arg, "sort", 4)) sort = SORT_ASC; else if (!strncasecmp(arg, "desc", 4)) sort = SORT_DESC; else { addReply(c, shared.syntaxerr); return; } } } /* Get all neighbor geohash boxes for our radius search */ GeoHashRadius georadius = geohashGetAreasByRadiusWGS84(latlong[0], latlong[1], radius_meters); #ifdef DEBUG printf("Searching with step size: %d\n", georadius.hash.step); #endif /* Search the zset for all matching points */ geoArray *ga = geoArrayCreate(); membersOfAllNeighbors(zobj, georadius, latlong[0], latlong[1], radius_meters, ga); /* If no matching results, the user gets an empty reply. */ if (ga->used == 0) { addReply(c, shared.emptymultibulk); geoArrayFree(ga); return; } long result_length = ga->used; long option_length = 0; /* Our options are self-contained nested multibulk replies, so we * only need to track how many of those nested replies we return. */ if (withdist) option_length++; if (withcoords) option_length++; if (withhash) option_length++; /* The multibulk len we send is exactly result_length. The result is either * all strings of just zset members *or* a nested multi-bulk reply * containing the zset member string _and_ all the additional options the * user enabled for this request. */ addReplyMultiBulkLen(c, result_length); /* Process [optional] requested sorting */ if (sort == SORT_ASC) { qsort(ga->array, result_length, sizeof(geoPoint), sort_gp_asc); } else if (sort == SORT_DESC) { qsort(ga->array, result_length, sizeof(geoPoint), sort_gp_desc); } /* Finally send results back to the caller */ int i; for (i = 0; i < result_length; i++) { geoPoint *gp = ga->array+i; gp->dist /= conversion; /* Fix according to unit. */ /* If we have options in option_length, return each sub-result * as a nested multi-bulk. Add 1 to account for result value itself. */ if (option_length) addReplyMultiBulkLen(c, option_length + 1); addReplyBulkSds(c,gp->member); gp->member = NULL; if (withdist) addReplyDoubleDistance(c, gp->dist); if (withhash) addReplyLongLong(c, gp->score); if (withcoords) { addReplyMultiBulkLen(c, 2); addReplyDouble(c, gp->latitude); addReplyDouble(c, gp->longitude); } } geoArrayFree(ga); } void geoRadiusCommand(redisClient *c) { /* args 0-5: ["georadius", key, lat, long, radius, units]; * optionals: [withdist, withcoords, asc|desc] */ geoRadiusGeneric(c, RADIUS_COORDS); } void geoRadiusByMemberCommand(redisClient *c) { /* args 0-4: ["georadius", key, compare-against-member, radius, units]; * optionals: [withdist, withcoords, asc|desc] */ geoRadiusGeneric(c, RADIUS_MEMBER); } void geoDecodeCommand(redisClient *c) { GeoHashBits geohash; if (getLongLongFromObjectOrReply(c, c->argv[1], (long long *)&geohash.bits, NULL) != REDIS_OK) return; GeoHashArea area; geohash.step = GEO_STEP_MAX; geohashDecodeWGS84(geohash, &area); double y = (area.latitude.min + area.latitude.max) / 2; double x = (area.longitude.min + area.longitude.max) / 2; /* Returning three nested replies */ addReplyMultiBulkLen(c, 3); /* First, the minimum corner */ addReplyMultiBulkLen(c, 2); addReplyDouble(c, area.latitude.min); addReplyDouble(c, area.longitude.min); /* Next, the maximum corner */ addReplyMultiBulkLen(c, 2); addReplyDouble(c, area.latitude.max); addReplyDouble(c, area.longitude.max); /* Last, the averaged center of this bounding box */ addReplyMultiBulkLen(c, 2); addReplyDouble(c, y); addReplyDouble(c, x); } void geoEncodeCommand(redisClient *c) { /* args 0-2: ["geoencode", lat, long]; * optionals: [radius, units] */ double radius_meters = 0; if (c->argc >= 5) { if ((radius_meters = extractDistanceOrReply(c, c->argv + 3, NULL)) < 0) return; } else if (c->argc == 4) { addReplyError(c, "must provide units when asking for radius encode"); return; } double latlong[2]; if (!extractLatLongOrReply(c, c->argv + 1, latlong)) return; /* Encode lat/long into our geohash */ GeoHashBits geohash; uint8_t step = geohashEstimateStepsByRadius(radius_meters); geohashEncodeWGS84(latlong[0], latlong[1], step, &geohash); /* Align the hash to a valid 52-bit integer based on step size */ GeoHashFix52Bits bits = geohashAlign52Bits(geohash); /* Decode the hash so we can return its bounding box */ #ifdef DEBUG printf("Decoding with step size: %d\n", geohash.step); #endif GeoHashArea area; geohashDecodeWGS84(geohash, &area); double y = (area.latitude.min + area.latitude.max) / 2; double x = (area.longitude.min + area.longitude.max) / 2; /* Return four nested multibulk replies. */ addReplyMultiBulkLen(c, 4); /* Return the binary geohash we calculated as 52-bit integer */ addReplyLongLong(c, bits); /* Return the minimum corner */ addReplyMultiBulkLen(c, 2); addReplyDouble(c, area.latitude.min); addReplyDouble(c, area.longitude.min); /* Return the maximum corner */ addReplyMultiBulkLen(c, 2); addReplyDouble(c, area.latitude.max); addReplyDouble(c, area.longitude.max); /* Return the averaged center */ addReplyMultiBulkLen(c, 2); addReplyDouble(c, y); addReplyDouble(c, x); }