/* * Copyright (c) 2014, Matt Stancliff . * Copyright (c) 2015, Salvatore Sanfilippo . * 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 * ==================================================================== */ /* ==================================================================== * 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 * ==================================================================== */ int decodeGeohash(double bits, double *xy) { GeoHashBits hash = { .bits = (uint64_t)bits, .step = GEO_STEP_MAX }; return geohashDecodeToLongLatWGS84(hash, xy); } /* Input Argument Helper */ /* Take a pointer to the latitude arg then use the next arg for longitude. * On parse error C_ERR is returned, otherwise C_OK. */ int extractLongLatOrReply(client *c, robj **argv, double *xy) { for (int i = 0; i < 2; i++) { if (getDoubleFromObjectOrReply(c, argv[i], xy + i, NULL) != C_OK) { return C_ERR; } if (xy[0] < GEO_LONG_MIN || xy[0] > GEO_LONG_MAX || xy[1] < GEO_LAT_MIN || xy[1] > GEO_LAT_MAX) { addReplySds(c, sdscatprintf(sdsempty(), "-ERR invalid longitude,latitude pair %f,%f\r\n",xy[0],xy[1])); return C_ERR; } } return C_OK; } /* Input Argument Helper */ /* Decode lat/long from a zset member's score. * Returns C_OK on successful decoding, otherwise C_ERR is returned. */ int longLatFromMember(robj *zobj, robj *member, double *xy) { double score = 0; if (zsetScore(zobj, member, &score) == C_ERR) return C_ERR; if (!decodeGeohash(score, xy)) return C_ERR; return C_OK; } /* Check that the unit argument matches one of the known units, and returns * the conversion factor to meters (you need to divide meters by the conversion * factor to convert to the right unit). * * If the unit is not valid, an error is reported to the client, and a value * less than zero is returned. */ double extractUnitOrReply(client *c, robj *unit) { char *u = unit->ptr; if (!strcmp(u, "m")) { return 1; } else if (!strcmp(u, "km")) { return 1000; } else if (!strcmp(u, "ft")) { return 0.3048; } else if (!strcmp(u, "mi")) { return 1609.34; } else { addReplyError(c, "unsupported unit provided. please use m, km, ft, mi"); return -1; } } /* Input Argument Helper. * Extract the dinstance from the specified two arguments starting at 'argv' * that shouldbe in the form: and return the dinstance in the * specified unit on success. *conversino is populated with the coefficient * to use in order to convert meters to the unit. * * On error a value less than zero is returned. */ double extractDistanceOrReply(client *c, robj **argv, double *conversion) { double distance; if (getDoubleFromObjectOrReply(c, argv[0], &distance, "need numeric radius") != C_OK) { return -1; } double to_meters = extractUnitOrReply(c,argv[1]); if (to_meters < 0) 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. */ void addReplyDoubleDistance(client *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 C_OK if the point is included, or REIDS_ERR if it is outside. */ int geoAppendIfWithinRadius(geoArray *ga, double lon, double lat, double radius, double score, sds member) { double distance, xy[2]; if (!decodeGeohash(score,xy)) return C_ERR; /* Can't decode. */ /* Note that geohashGetDistanceIfInRadiusWGS84() takes arguments in * reverse order: longitude first, latitude later. */ if (!geohashGetDistanceIfInRadiusWGS84(lon,lat, xy[0], xy[1], radius, &distance)) { return C_ERR; } /* Append the new element. */ geoPoint *gp = geoArrayAppend(ga); gp->longitude = xy[0]; gp->latitude = xy[1]; gp->dist = distance; gp->member = member; gp->score = score; return C_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 lon, double lat, 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 == OBJ_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,lon,lat,radius,score,member) == C_ERR) sdsfree(member); zzlNext(zl, &eptr, &sptr); } } else if (zobj->encoding == OBJ_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 == OBJ_ENCODING_INT) ? sdsfromlonglong((long)o->ptr) : sdsdup(o->ptr); if (geoAppendIfWithinRadius(ga,lon,lat,radius,ln->score,member) == C_ERR) sdsfree(member); ln = ln->level[0].forward; } } return ga->used - origincount; } /* Compute the sorted set scores min (inclusive), max (exclusive) we should * query in order to retrieve all the elements inside the specified area * 'hash'. The two scores are returned by reference in *min and *max. */ void scoresOfGeoHashBox(GeoHashBits hash, GeoHashFix52Bits *min, GeoHashFix52Bits *max) { /* We want to compute the sorted set scores that will include all the * elements inside the specified Geohash 'hash', which has as many * bits as specified by hash.step * 2. * * So if step is, for example, 3, and the hash value in binary * is 101010, since our score is 52 bits we want every element which * is in binary: 101010????????????????????????????????????????????? * Where ? can be 0 or 1. * * To get the min score we just use the initial hash value left * shifted enough to get the 52 bit value. Later we increment the * 6 bit prefis (see the hash.bits++ statement), and get the new * prefix: 101011, which we align again to 52 bits to get the maximum * value (which is excluded from the search). So we get everything * between the two following scores (represented in binary): * * 1010100000000000000000000000000000000000000000000000 (included) * and * 1010110000000000000000000000000000000000000000000000 (excluded). */ *min = geohashAlign52Bits(hash); hash.bits++; *max = geohashAlign52Bits(hash); } /* 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 lon, double lat, double radius) { GeoHashFix52Bits min, max; scoresOfGeoHashBox(hash,&min,&max); return geoGetPointsInRange(zobj, min, max, lon, lat, radius, ga); } /* Search all eight neighbors + self geohash box */ int membersOfAllNeighbors(robj *zobj, GeoHashRadius n, double lon, double lat, 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, lon, lat, 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 * ==================================================================== */ /* GEOADD key long lat name [long2 lat2 name2 ... longN latN nameN] */ void geoaddCommand(client *c) { /* Check arguments number for sanity. */ if ((c->argc - 2) % 3 != 0) { /* Need an odd number of arguments if we got this far... */ addReplyError(c, "syntax error. Try GEOADD key [x1] [y1] [name1] " "[x2] [y2] [name2] ... "); return; } int elements = (c->argc - 2) / 3; int argc = 2+elements*2; /* ZADD key score ele ... */ robj **argv = zcalloc(argc*sizeof(robj*)); argv[0] = createRawStringObject("zadd",4); argv[1] = c->argv[1]; /* key */ incrRefCount(argv[1]); /* Create the argument vector to call ZADD in order to add all * the score,value pairs to the requested zset, where score is actually * an encoded version of lat,long. */ int i; for (i = 0; i < elements; i++) { double xy[2]; if (extractLongLatOrReply(c, (c->argv+2)+(i*3),xy) == C_ERR) { for (i = 0; i < argc; i++) if (argv[i]) decrRefCount(argv[i]); zfree(argv); return; } /* Turn the coordinates into the score of the element. */ GeoHashBits hash; geohashEncodeWGS84(xy[0], xy[1], GEO_STEP_MAX, &hash); GeoHashFix52Bits bits = geohashAlign52Bits(hash); robj *score = createObject(OBJ_STRING, sdsfromlonglong(bits)); robj *val = c->argv[2 + i * 3 + 2]; argv[2+i*2] = score; argv[3+i*2] = val; incrRefCount(val); } /* Finally call ZADD that will do the work for us. */ replaceClientCommandVector(c,argc,argv); zaddCommand(c); } #define SORT_NONE 0 #define SORT_ASC 1 #define SORT_DESC 2 #define RADIUS_COORDS 1 #define RADIUS_MEMBER 2 /* GEORADIUS key x y radius unit [WITHDIST] [WITHHASH] [WITHCOORD] [ASC|DESC] * [COUNT count] * GEORADIUSBYMEMBER key member radius unit ... options ... */ void georadiusGeneric(client *c, int type) { robj *key = c->argv[1]; /* Look up the requested zset */ robj *zobj = NULL; if ((zobj = lookupKeyReadOrReply(c, key, shared.emptymultibulk)) == NULL || checkType(c, zobj, OBJ_ZSET)) { return; } /* Find long/lat to use for radius search based on inquiry type */ int base_args; double xy[2] = { 0 }; if (type == RADIUS_COORDS) { base_args = 6; if (extractLongLatOrReply(c, c->argv + 2, xy) == C_ERR) return; } else if (type == RADIUS_MEMBER) { base_args = 5; robj *member = c->argv[2]; if (longLatFromMember(zobj, member, xy) == C_ERR) { 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; int sort = SORT_NONE; long long count = 0; 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 (!strcasecmp(arg, "withdist")) { withdist = 1; } else if (!strcasecmp(arg, "withhash")) { withhash = 1; } else if (!strcasecmp(arg, "withcoord")) { withcoords = 1; } else if (!strcasecmp(arg, "asc")) { sort = SORT_ASC; } else if (!strcasecmp(arg, "desc")) { sort = SORT_DESC; } else if (!strcasecmp(arg, "count") && remaining > 0) { if (getLongLongFromObjectOrReply(c, c->argv[base_args+i+1], &count, NULL) != C_OK) return; if (count <= 0) { addReplyError(c,"COUNT must be > 0"); return; } i++; } else { addReply(c, shared.syntaxerr); return; } } } /* COUNT without ordering does not make much sense, force ASC * ordering if COUNT was specified but no sorting was requested. */ if (count != 0 && sort == SORT_NONE) sort = SORT_ASC; /* Get all neighbor geohash boxes for our radius search */ GeoHashRadius georadius = geohashGetAreasByRadiusWGS84(xy[0], xy[1], radius_meters); /* Search the zset for all matching points */ geoArray *ga = geoArrayCreate(); membersOfAllNeighbors(zobj, georadius, xy[0], xy[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, (count == 0 || result_length < count) ? result_length : count); /* 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->longitude); addReplyDouble(c, gp->latitude); } /* Stop if COUNT was specified and we already provided the * specified number of elements. */ if (count != 0 && count == i+1) break; } geoArrayFree(ga); } /* GEORADIUS wrapper function. */ void georadiusCommand(client *c) { georadiusGeneric(c, RADIUS_COORDS); } /* GEORADIUSBYMEMBER wrapper function. */ void georadiusByMemberCommand(client *c) { georadiusGeneric(c, RADIUS_MEMBER); } /* GEOHASH key ele1 ele2 ... eleN * * Returns an array with an 11 characters geohash representation of the * position of the specified elements. */ void geohashCommand(client *c) { char *geoalphabet= "0123456789bcdefghjkmnpqrstuvwxyz"; int j; /* Look up the requested zset */ robj *zobj = NULL; if ((zobj = lookupKeyReadOrReply(c, c->argv[1], shared.emptymultibulk)) == NULL || checkType(c, zobj, OBJ_ZSET)) return; /* Geohash elements one after the other, using a null bulk reply for * missing elements. */ addReplyMultiBulkLen(c,c->argc-2); for (j = 2; j < c->argc; j++) { double score; if (zsetScore(zobj, c->argv[j], &score) == C_ERR) { addReply(c,shared.nullbulk); } else { /* The internal format we use for geocoding is a bit different * than the standard, since we use as initial latitude range * -85,85, while the normal geohashing algorithm uses -90,90. * So we have to decode our position and re-encode using the * standard ranges in order to output a valid geohash string. */ /* Decode... */ double xy[2]; if (!decodeGeohash(score,xy)) { addReply(c,shared.nullbulk); continue; } /* Re-encode */ GeoHashRange r[2]; GeoHashBits hash; r[0].min = -180; r[0].max = 180; r[1].min = -90; r[1].max = 90; geohashEncode(&r[0],&r[1],xy[0],xy[1],26,&hash); char buf[12]; int i; for (i = 0; i < 11; i++) { int idx = (hash.bits >> (52-((i+1)*5))) & 0x1f; buf[i] = geoalphabet[idx]; } buf[11] = '\0'; addReplyBulkCBuffer(c,buf,11); } } } /* GEOPOS key ele1 ele2 ... eleN * * Returns an array of two-items arrays representing the x,y position of each * element specified in the arguments. For missing elements NULL is returned. */ void geoposCommand(client *c) { int j; /* Look up the requested zset */ robj *zobj = NULL; if ((zobj = lookupKeyReadOrReply(c, c->argv[1], shared.emptymultibulk)) == NULL || checkType(c, zobj, OBJ_ZSET)) return; /* Report elements one after the other, using a null bulk reply for * missing elements. */ addReplyMultiBulkLen(c,c->argc-2); for (j = 2; j < c->argc; j++) { double score; if (zsetScore(zobj, c->argv[j], &score) == C_ERR) { addReply(c,shared.nullmultibulk); } else { /* Decode... */ double xy[2]; if (!decodeGeohash(score,xy)) { addReply(c,shared.nullmultibulk); continue; } addReplyMultiBulkLen(c,2); addReplyDouble(c,xy[0]); addReplyDouble(c,xy[1]); } } } /* GEODIST key ele1 ele2 [unit] * * Return the distance, in meters by default, otherwise accordig to "unit", * between points ele1 and ele2. If one or more elements are missing NULL * is returned. */ void geodistCommand(client *c) { double to_meter = 1; /* Check if there is the unit to extract, otherwise assume meters. */ if (c->argc == 5) { to_meter = extractUnitOrReply(c,c->argv[4]); if (to_meter < 0) return; } else if (c->argc > 5) { addReply(c,shared.syntaxerr); return; } /* Look up the requested zset */ robj *zobj = NULL; if ((zobj = lookupKeyReadOrReply(c, c->argv[1], shared.emptybulk)) == NULL || checkType(c, zobj, OBJ_ZSET)) return; /* Get the scores. We need both otherwise NULL is returned. */ double score1, score2, xyxy[4]; if (zsetScore(zobj, c->argv[2], &score1) == C_ERR || zsetScore(zobj, c->argv[3], &score2) == C_ERR) { addReply(c,shared.nullbulk); return; } /* Decode & compute the distance. */ if (!decodeGeohash(score1,xyxy) || !decodeGeohash(score2,xyxy+2)) addReply(c,shared.nullbulk); else addReplyDouble(c, geohashGetDistance(xyxy[0],xyxy[1],xyxy[2],xyxy[3]) / to_meter); }