From 71b15249b36e8408d48531d89a01cc7d7b044ebe Mon Sep 17 00:00:00 2001 From: Emile Date: Wed, 13 Feb 2019 22:36:23 +0100 Subject: working! --- db_actions/db_actions.go | 883 ----------------------------------------------- 1 file changed, 883 deletions(-) delete mode 100644 db_actions/db_actions.go (limited to 'db_actions/db_actions.go') diff --git a/db_actions/db_actions.go b/db_actions/db_actions.go deleted file mode 100644 index 561ce56..0000000 --- a/db_actions/db_actions.go +++ /dev/null @@ -1,883 +0,0 @@ -// db_actions defines actions on the database -// Copyright (C) 2019 Emile Hansmaennel -// -// This program is free software: you can redistribute it and/or modify -// it under the terms of the GNU General Public License as published by -// the Free Software Foundation, either version 3 of the License, or -// (at your option) any later version. -// -// This program is distributed in the hope that it will be useful, -// but WITHOUT ANY WARRANTY; without even the implied warranty of -// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the -// GNU General Public License for more details. -// -// You should have received a copy of the GNU General Public License -// along with this program. If not, see . - -package db_actions - -import ( - "database/sql" - "encoding/csv" - "fmt" - "git.darknebu.la/GalaxySimulator/structs" - _ "github.com/lib/pq" - "io" - "io/ioutil" - "log" - "strconv" - "strings" - "time" -) - -const ( - DBUSER = "postgres" - DBNAME = "postgres" - DBSSLMODE = "disable" -) - -var ( - db *sql.DB -) - -// connectToDB returns a pointer to an sql database writing to the database -func ConnectToDB() *sql.DB { - connStr := fmt.Sprintf("user=%s dbname=%s sslmode=%s", DBUSER, DBNAME, DBSSLMODE) - db := dbConnect(connStr) - return db -} - -// dbConnect connects to a PostgreSQL database -func dbConnect(connStr string) *sql.DB { - // connect to the database - db, err := sql.Open("postgres", connStr) - if err != nil { - log.Fatalf("[ E ] connection: %v", err) - } - - return db -} - -// newTree creates a new tree with the given width -func NewTree(database *sql.DB, width float64) { - db = database - // get the current max root id - query := fmt.Sprintf("SELECT COALESCE(max(root_id), 0) FROM nodes") - var currentMaxRootID int64 - err := db.QueryRow(query).Scan(¤tMaxRootID) - if err != nil { - log.Fatalf("[ E ] max root id query: %v\n\t\t\t query: %s\n", err, query) - } - - // build the query creating a new node - query = fmt.Sprintf("INSERT INTO nodes (box_width, root_id, box_center, depth, isleaf) VALUES (%f, %d, '{0, 0}', 0, TRUE)", width, currentMaxRootID+1) - - // execute the query - rows, err := db.Query(query) - defer rows.Close() - if err != nil { - log.Fatalf("[ E ] insert new node query: %v\n\t\t\t query: %s\n", err, query) - } -} - -// insertStar inserts the given star into the stars table and the nodes table tree -func InsertStar(database *sql.DB, star structs.Star2D, index int64) { - db = database - start := time.Now() - // insert the star into the stars table - starID := insertIntoStars(star) - - // get the root node id - query := fmt.Sprintf("SELECT node_id FROM nodes WHERE root_id=%d", index) - var id int64 - err := db.QueryRow(query).Scan(&id) - if err != nil { - log.Fatalf("[ E ] Get root node id query: %v\n\t\t\t query: %s\n", err, query) - } - - // insert the star into the tree (using it's ID) starting at the root - insertIntoTree(starID, id) - elapsedTime := time.Since(start) - log.Printf("\t\t\t\t\t %s", elapsedTime) -} - -// insertIntoStars inserts the given star into the stars table -func insertIntoStars(star structs.Star2D) int64 { - // unpack the star - x := star.C.X - y := star.C.Y - vx := star.V.X - vy := star.V.Y - m := star.M - - // build the request query - query := fmt.Sprintf("INSERT INTO stars (x, y, vx, vy, m) VALUES (%f, %f, %f, %f, %f) RETURNING star_id", x, y, vx, vy, m) - - // execute the query - var starID int64 - err := db.QueryRow(query).Scan(&starID) - if err != nil { - log.Fatalf("[ E ] insert query: %v\n\t\t\t query: %s\n", err, query) - } - - return starID -} - -// insert into tree inserts the given star into the tree starting at the node with the given node id -func insertIntoTree(starID int64, nodeID int64) { - //starRaw := getStar(starID) - //nodeCenter := getBoxCenter(nodeID) - //nodeWidth := getBoxWidth(nodeID) - //log.Printf("[ ] \t Inserting star %v into the node (c: %v, w: %v)", starRaw, nodeCenter, nodeWidth) - - // There exist four cases: - // | Contains a Star | Does not Contain a Star | - // ------------------ + --------------- + ----------------------- + - // Node is a Leaf | Impossible | insert into node | - // | | subdivide | - // ------------------ + --------------- + ----------------------- + - // Node is not a Leaf | insert preexist | insert into the subtree | - // | insert new | | - // ------------------ + --------------- + ----------------------- + - - // get the node with the given nodeID - // find out if the node contains a star or not - containsStar := containsStar(nodeID) - - // find out if the node is a leaf - isLeaf := isLeaf(nodeID) - - // if the node is a leaf and contains a star - // subdivide the tree - // insert the preexisting star into the correct subtree - // insert the new star into the subtree - if isLeaf == true && containsStar == true { - //log.Printf("Case 1, \t %v \t %v", nodeWidth, nodeCenter) - subdivide(nodeID) - //tree := printTree(nodeID) - - // Stage 1: Inserting the blocking star - blockingStarID := getStarID(nodeID) // get the id of the star blocking the node - blockingStar := getStar(blockingStarID) // get the actual star - blockingStarQuadrant := quadrant(blockingStar, nodeID) // find out in which quadrant it belongs - quadrantNodeID := getQuadrantNodeID(nodeID, blockingStarQuadrant) // get the nodeID of that quadrant - insertIntoTree(blockingStarID, quadrantNodeID) // insert the star into that node - removeStarFromNode(nodeID) // remove the blocking star from the node it was blocking - - // Stage 1: Inserting the actual star - star := getStar(starID) // get the actual star - starQuadrant := quadrant(star, nodeID) // find out in which quadrant it belongs - quadrantNodeID = getQuadrantNodeID(nodeID, starQuadrant) // get the nodeID of that quadrant - insertIntoTree(starID, nodeID) - } - - // if the node is a leaf and does not contain a star - // insert the star into the node and subdivide it - if isLeaf == true && containsStar == false { - //log.Printf("Case 2, \t %v \t %v", nodeWidth, nodeCenter) - directInsert(starID, nodeID) - } - - // if the node is not a leaf and contains a star - // insert the preexisting star into the correct subtree - // insert the new star into the subtree - if isLeaf == false && containsStar == true { - //log.Printf("Case 3, \t %v \t %v", nodeWidth, nodeCenter) - // Stage 1: Inserting the blocking star - blockingStarID := getStarID(nodeID) // get the id of the star blocking the node - blockingStar := getStar(blockingStarID) // get the actual star - blockingStarQuadrant := quadrant(blockingStar, nodeID) // find out in which quadrant it belongs - quadrantNodeID := getQuadrantNodeID(nodeID, blockingStarQuadrant) // get the nodeID of that quadrant - insertIntoTree(blockingStarID, quadrantNodeID) // insert the star into that node - removeStarFromNode(nodeID) // remove the blocking star from the node it was blocking - - // Stage 1: Inserting the actual star - star := getStar(blockingStarID) // get the actual star - starQuadrant := quadrant(star, nodeID) // find out in which quadrant it belongs - quadrantNodeID = getQuadrantNodeID(nodeID, starQuadrant) // get the nodeID of that quadrant - insertIntoTree(starID, nodeID) - } - - // if the node is not a leaf and does not contain a star - // insert the new star into the according subtree - if isLeaf == false && containsStar == false { - //log.Printf("Case 4, \t %v \t %v", nodeWidth, nodeCenter) - star := getStar(starID) // get the actual star - starQuadrant := quadrant(star, nodeID) // find out in which quadrant it belongs - quadrantNodeID := getQuadrantNodeID(nodeID, starQuadrant) // get the if of that quadrant - insertIntoTree(starID, quadrantNodeID) // insert the star into that quadrant - } -} - -// containsStar returns true if the node with the given id contains a star and returns false if not. -func containsStar(id int64) bool { - var starID int64 - - query := fmt.Sprintf("SELECT star_id FROM nodes WHERE node_id=%d", id) - err := db.QueryRow(query).Scan(&starID) - if err != nil { - log.Fatalf("[ E ] containsStar query: %v\n\t\t\t query: %s\n", err, query) - } - - if starID != 0 { - return true - } - - return false -} - -// isLeaf returns true if the node with the given id is a leaf -func isLeaf(nodeID int64) bool { - var isLeaf bool - - query := fmt.Sprintf("SELECT COALESCE(isleaf, FALSE) FROM nodes WHERE node_id=%d", nodeID) - err := db.QueryRow(query).Scan(&isLeaf) - if err != nil { - log.Fatalf("[ E ] isLeaf query: %v\n\t\t\t query: %s\n", err, query) - } - - if isLeaf == true { - return true - } - - return false -} - -// directInsert inserts the star with the given ID into the given node inside of the given database -func directInsert(starID int64, nodeID int64) { - // build the query - query := fmt.Sprintf("UPDATE nodes SET star_id=%d WHERE node_id=%d", starID, nodeID) - - // Execute the query - rows, err := db.Query(query) - defer rows.Close() - if err != nil { - log.Fatalf("[ E ] directInsert query: %v\n\t\t\t query: %s\n", err, query) - } -} - -// subdivide subdivides the given node creating four child nodes -func subdivide(nodeID int64) { - boxWidth := getBoxWidth(nodeID) - boxCenter := getBoxCenter(nodeID) - originalDepth := getNodeDepth(nodeID) - - // calculate the new positions - newPosX := boxCenter[0] + (boxWidth / 2) - newPosY := boxCenter[1] + (boxWidth / 2) - newNegX := boxCenter[0] - (boxWidth / 2) - newNegY := boxCenter[1] - (boxWidth / 2) - newWidth := boxWidth / 2 - - // create new news with those positions - newNodeIDA := newNode(newPosX, newPosY, newWidth, originalDepth+1) - newNodeIDB := newNode(newPosX, newNegY, newWidth, originalDepth+1) - newNodeIDC := newNode(newNegX, newPosY, newWidth, originalDepth+1) - newNodeIDD := newNode(newNegX, newNegY, newWidth, originalDepth+1) - - // Update the subtrees of the parent node - - // build the query - query := fmt.Sprintf("UPDATE nodes SET subnode='{%d, %d, %d, %d}', isleaf=FALSE WHERE node_id=%d", newNodeIDA, newNodeIDB, newNodeIDC, newNodeIDD, nodeID) - - // Execute the query - rows, err := db.Query(query) - defer rows.Close() - if err != nil { - log.Fatalf("[ E ] subdivide query: %v\n\t\t\t query: %s\n", err, query) - } -} - -// getBoxWidth gets the width of the box from the node width the given id -func getBoxWidth(nodeID int64) float64 { - var boxWidth float64 - - query := fmt.Sprintf("SELECT box_width FROM nodes WHERE node_id=%d", nodeID) - err := db.QueryRow(query).Scan(&boxWidth) - if err != nil { - log.Fatalf("[ E ] getBoxWidth query: %v\n\t\t\t query: %s\n", err, query) - } - - return boxWidth -} - -// getBoxWidth gets the center of the box from the node width the given id -func getBoxCenter(nodeID int64) []float64 { - var boxCenterX, boxCenterY []uint8 - - query := fmt.Sprintf("SELECT box_center[1], box_center[2] FROM nodes WHERE node_id=%d", nodeID) - err := db.QueryRow(query).Scan(&boxCenterX, &boxCenterY) - if err != nil { - log.Fatalf("[ E ] getBoxCenter query: %v\n\t\t\t query: %s\n", err, query) - } - - x, parseErr := strconv.ParseFloat(string(boxCenterX), 64) - y, parseErr := strconv.ParseFloat(string(boxCenterX), 64) - - if parseErr != nil { - log.Fatalf("[ E ] parse boxCenter: %v\n\t\t\t query: %s\n", err, query) - log.Fatalf("[ E ] parse boxCenter: (%f, %f)\n", x, y) - } - - boxCenterFloat := []float64{x, y} - - return boxCenterFloat -} - -// newNode Inserts a new node into the database with the given parameters -func newNode(x float64, y float64, width float64, depth int64) int64 { - // build the query creating a new node - query := fmt.Sprintf("INSERT INTO nodes (box_center, box_width, depth, isleaf) VALUES ('{%f, %f}', %f, %d, TRUE) RETURNING node_id", x, y, width, depth) - - var nodeID int64 - - // execute the query - err := db.QueryRow(query).Scan(&nodeID) - if err != nil { - log.Fatalf("[ E ] newNode query: %v\n\t\t\t query: %s\n", err, query) - } - - return nodeID -} - -// getStarID returns the id of the star inside of the node with the given ID -func getStarID(nodeID int64) int64 { - // get the star id from the node - var starID int64 - query := fmt.Sprintf("SELECT star_id FROM nodes WHERE node_id=%d", nodeID) - err := db.QueryRow(query).Scan(&starID) - if err != nil { - log.Fatalf("[ E ] getStarID id query: %v\n\t\t\t query: %s\n", err, query) - } - - return starID -} - -// deleteAll Stars deletes all the rows in the stars table -func DeleteAllStars(database *sql.DB) { - db = database - // build the query creating a new node - query := "DELETE FROM stars WHERE TRUE" - - // execute the query - rows, err := db.Query(query) - defer rows.Close() - if err != nil { - log.Fatalf("[ E ] deleteAllStars query: %v\n\t\t\t query: %s\n", err, query) - } -} - -// deleteAll Stars deletes all the rows in the nodes table -func DeleteAllNodes(database *sql.DB) { - db = database - // build the query creating a new node - query := "DELETE FROM nodes WHERE TRUE" - - // execute the query - _, err := db.Query(query) - if err != nil { - log.Fatalf("[ E ] deleteAllStars query: %v\n\t\t\t query: %s\n", err, query) - } -} - -// getNodeDepth returns the depth of the given node in the tree -func getNodeDepth(nodeID int64) int64 { - // build the query - query := fmt.Sprintf("SELECT depth FROM nodes WHERE node_id=%d", nodeID) - - var depth int64 - - // Execute the query - err := db.QueryRow(query).Scan(&depth) - if err != nil { - log.Fatalf("[ E ] getNodeDepth query: %v \n\t\t\t query: %s\n", err, query) - } - - return depth -} - -// quadrant returns the quadrant into which the given star belongs -func quadrant(star structs.Star2D, nodeID int64) int64 { - // get the center of the node the star is in - center := getBoxCenter(nodeID) - centerX := center[0] - centerY := center[1] - - if star.C.X > centerX { - if star.C.Y > centerY { - // North East condition - return 1 - } - // South East condition - return 3 - } - - if star.C.Y > centerY { - // North West condition - return 0 - } - // South West condition - return 2 -} - -// getQuadrantNodeID returns the id of the requested child-node -// Example: if a parent has four children and quadrant 0 is requested, the function returns the north east child id -func getQuadrantNodeID(parentNodeID int64, quadrant int64) int64 { - var a, b, c, d []uint8 - - // get the star from the stars table - query := fmt.Sprintf("SELECT subnode[1], subnode[2], subnode[3], subnode[4] FROM nodes WHERE node_id=%d", parentNodeID) - err := db.QueryRow(query).Scan(&a, &b, &c, &d) - if err != nil { - log.Fatalf("[ E ] getQuadrantNodeID star query: %v \n\t\t\tquery: %s\n", err, query) - } - - returnA, _ := strconv.ParseInt(string(a), 10, 64) - returnB, _ := strconv.ParseInt(string(b), 10, 64) - returnC, _ := strconv.ParseInt(string(c), 10, 64) - returnD, _ := strconv.ParseInt(string(d), 10, 64) - - switch quadrant { - case 0: - return returnA - case 1: - return returnB - case 2: - return returnC - case 3: - return returnD - } - - return -1 -} - -// getStar returns the star with the given ID from the stars table -func getStar(starID int64) structs.Star2D { - var x, y, vx, vy, m float64 - - // get the star from the stars table - query := fmt.Sprintf("SELECT x, y, vx, vy, m FROM stars WHERE star_id=%d", starID) - err := db.QueryRow(query).Scan(&x, &y, &vx, &vy, &m) - if err != nil { - log.Fatalf("[ E ] getStar query: %v \n\t\t\tquery: %s\n", err, query) - } - - star := structs.Star2D{ - C: structs.Vec2{ - X: x, - Y: y, - }, - V: structs.Vec2{ - X: vx, - Y: vy, - }, - M: m, - } - - return star -} - -// getStarMass returns the mass if the star with the given ID -func getStarMass(starID int64) float64 { - var mass float64 - - // get the star from the stars table - query := fmt.Sprintf("SELECT m FROM stars WHERE star_id=%d", starID) - err := db.QueryRow(query).Scan(&mass) - if err != nil { - log.Fatalf("[ E ] getStarMass query: %v \n\t\t\tquery: %s\n", err, query) - } - - return mass -} - -// getNodeTotalMass returns the total mass of the node with the given ID and its children -func getNodeTotalMass(nodeID int64) float64 { - var mass float64 - - // get the star from the stars table - query := fmt.Sprintf("SELECT total_mass FROM nodes WHERE node_id=%d", nodeID) - err := db.QueryRow(query).Scan(&mass) - if err != nil { - log.Fatalf("[ E ] getStarMass query: %v \n\t\t\tquery: %s\n", err, query) - } - - return mass -} - -// removeStarFromNode removes the star from the node with the given ID -func removeStarFromNode(nodeID int64) { - // build the query - query := fmt.Sprintf("UPDATE nodes SET star_id=0 WHERE node_id=%d", nodeID) - - // Execute the query - rows, err := db.Query(query) - defer rows.Close() - if err != nil { - log.Fatalf("[ E ] removeStarFromNode query: %v\n\t\t\t query: %s\n", err, query) - } -} - -// getListOfStarsGo returns the list of stars in go struct format -func GetListOfStarsGo(database *sql.DB) []structs.Star2D { - db = database - // build the query - query := fmt.Sprintf("SELECT * FROM stars") - - // Execute the query - rows, err := db.Query(query) - defer rows.Close() - if err != nil { - log.Fatalf("[ E ] removeStarFromNode query: %v\n\t\t\t query: %s\n", err, query) - } - - var starList []structs.Star2D - - // iterate over the returned rows - for rows.Next() { - - var starID int64 - var x, y, vx, vy, m float64 - scanErr := rows.Scan(&starID, &x, &y, &vx, &vy, &m) - if scanErr != nil { - log.Fatalf("[ E ] scan error: %v", scanErr) - } - - star := structs.Star2D{ - C: structs.Vec2{ - X: x, - Y: y, - }, - V: structs.Vec2{ - X: vx, - Y: vy, - }, - M: m, - } - - starList = append(starList, star) - } - - return starList -} - -// getListOfStarsCsv returns an array of strings containing the coordinates of all the stars in the stars table -func GetListOfStarsCsv(database *sql.DB) []string { - db = database - // build the query - query := fmt.Sprintf("SELECT * FROM stars") - - // Execute the query - rows, err := db.Query(query) - defer rows.Close() - if err != nil { - log.Fatalf("[ E ] removeStarFromNode query: %v\n\t\t\t query: %s\n", err, query) - } - - var starList []string - - // iterate over the returned rows - for rows.Next() { - - var starID int64 - var x, y, vx, vy, m float64 - scanErr := rows.Scan(&starID, &x, &y, &vx, &vy, &m) - if scanErr != nil { - log.Fatalf("[ E ] scan error: %v", scanErr) - } - - row := fmt.Sprintf("%d, %f, %f, %f, %f, %f", starID, x, y, vx, vy, m) - starList = append(starList, row) - } - - return starList -} - -// insertList inserts all the stars in the given .csv into the stars and nodes table -func InsertList(database *sql.DB, filename string) { - db = database - // open the file - content, readErr := ioutil.ReadFile(filename) - if readErr != nil { - panic(readErr) - } - - in := string(content) - reader := csv.NewReader(strings.NewReader(in)) - - // insert all the stars into the db - for { - record, err := reader.Read() - if err == io.EOF { - log.Println("EOF") - break - } - if err != nil { - log.Println("insertListErr") - panic(err) - } - - x, _ := strconv.ParseFloat(record[0], 64) - y, _ := strconv.ParseFloat(record[1], 64) - - star := structs.Star2D{ - C: structs.Vec2{ - X: x / 100000, - Y: y / 100000, - }, - V: structs.Vec2{ - X: 0, - Y: 0, - }, - M: 1000, - } - - fmt.Printf("Inserting (%f, %f)\n", star.C.X, star.C.Y) - InsertStar(db, star, 1) - } -} - -// getRootNodeID gets a tree index and returns the nodeID of its root node -func getRootNodeID(index int64) int64 { - var nodeID int64 - - query := fmt.Sprintf("SELECT node_id FROM nodes WHERE root_id=%d", index) - err := db.QueryRow(query).Scan(&nodeID) - if err != nil { - log.Fatalf("[ E ] getRootNodeID query: %v\n\t\t\t query: %s\n", err, query) - } - - return nodeID -} - -// updateTotalMass gets a tree index and returns the nodeID of the trees root node -func UpdateTotalMass(database *sql.DB, index int64) { - db = database - rootNodeID := getRootNodeID(index) - log.Printf("RootID: %d", rootNodeID) - updateTotalMassNode(rootNodeID) -} - -// updateTotalMassNode updates the total mass of the given node -func updateTotalMassNode(nodeID int64) float64 { - var totalmass float64 - - // get the subnode ids - var subnode [4]int64 - - query := fmt.Sprintf("SELECT subnode[1], subnode[2], subnode[3], subnode[4] FROM nodes WHERE node_id=%d", nodeID) - err := db.QueryRow(query).Scan(&subnode[0], &subnode[1], &subnode[2], &subnode[3]) - if err != nil { - log.Fatalf("[ E ] updateTotalMassNode query: %v\n\t\t\t query: %s\n", err, query) - } - - // iterate over all subnodes updating their total masses - for _, subnodeID := range subnode { - fmt.Println("----------------------------") - fmt.Printf("SubdnodeID: %d\n", subnodeID) - if subnodeID != 0 { - totalmass += updateTotalMassNode(subnodeID) - } else { - // get the starID for getting the star mass - starID := getStarID(nodeID) - fmt.Printf("StarID: %d\n", starID) - if starID != 0 { - mass := getStarMass(starID) - log.Printf("starID=%d \t mass: %f", starID, mass) - totalmass += mass - } - - // break, this stops a star from being counted multiple (4) times - break - } - fmt.Println("----------------------------") - } - - query = fmt.Sprintf("UPDATE nodes SET total_mass=%f WHERE node_id=%d", totalmass, nodeID) - rows, err := db.Query(query) - defer rows.Close() - if err != nil { - log.Fatalf("[ E ] insert total_mass query: %v\n\t\t\t query: %s\n", err, query) - } - - fmt.Printf("nodeID: %d \t totalMass: %f\n", nodeID, totalmass) - - return totalmass -} - -// updateCenterOfMass recursively updates the center of mass of all the nodes starting at the node with the given -// root index -func UpdateCenterOfMass(database *sql.DB, index int64) { - db = database - rootNodeID := getRootNodeID(index) - log.Printf("RootID: %d", rootNodeID) - updateCenterOfMassNode(rootNodeID) -} - -// updateCenterOfMassNode updates the center of mass of the node with the given nodeID recursively -// center of mass := ((x_1 * m) + (x_2 * m) + ... + (x_n * m)) / m -func updateCenterOfMassNode(nodeID int64) structs.Vec2 { - fmt.Println("++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++") - - var centerOfMass structs.Vec2 - - // get the subnode ids - var subnode [4]int64 - var starID int64 - - query := fmt.Sprintf("SELECT subnode[1], subnode[2], subnode[3], subnode[4], star_id FROM nodes WHERE node_id=%d", nodeID) - err := db.QueryRow(query).Scan(&subnode[0], &subnode[1], &subnode[2], &subnode[3], &starID) - if err != nil { - log.Fatalf("[ E ] updateCenterOfMassNode query: %v\n\t\t\t query: %s\n", err, query) - } - - // if the nodes does not contain a star but has children, update the center of mass - if subnode != ([4]int64{0, 0, 0, 0}) { - log.Println("[ ] recursing deeper") - - // define variables storing the values of the subnodes - var totalMass float64 - var centerOfMassX float64 - var centerOfMassY float64 - - // iterate over all the subnodes and calculate the center of mass of each node - for _, subnodeID := range subnode { - subnodeCenterOfMass := updateCenterOfMassNode(subnodeID) - - if subnodeCenterOfMass.X != 0 && subnodeCenterOfMass.Y != 0 { - fmt.Printf("SubnodeCenterOfMass: (%f, %f)\n", subnodeCenterOfMass.X, subnodeCenterOfMass.Y) - subnodeMass := getNodeTotalMass(subnodeID) - totalMass += subnodeMass - - centerOfMassX += subnodeCenterOfMass.X * subnodeMass - centerOfMassY += subnodeCenterOfMass.Y * subnodeMass - } - } - - // calculate the overall center of mass of the subtree - centerOfMass = structs.Vec2{ - X: centerOfMassX / totalMass, - Y: centerOfMassY / totalMass, - } - - // else, use the star as the center of mass (this can be done, because of the rule defining that there - // can only be one star in a cell) - } else { - log.Println("[ ] using the star in the node as the center of mass") - log.Printf("[ ] NodeID: %v", nodeID) - starID := getStarID(nodeID) - - if starID == 0 { - log.Println("[ ] StarID == 0...") - centerOfMass = structs.Vec2{ - X: 0, - Y: 0, - } - } else { - log.Printf("[ ] NodeID: %v", starID) - star := getStar(starID) - centerOfMassX := star.C.X - centerOfMassY := star.C.Y - centerOfMass = structs.Vec2{ - X: centerOfMassX, - Y: centerOfMassY, - } - } - } - - // build the query - query = fmt.Sprintf("UPDATE nodes SET center_of_mass='{%f, %f}' WHERE node_id=%d", centerOfMass.X, centerOfMass.Y, nodeID) - - // Execute the query - rows, err := db.Query(query) - defer rows.Close() - if err != nil { - log.Fatalf("[ E ] update center of mass query: %v\n\t\t\t query: %s\n", err, query) - } - - fmt.Printf("[ ] CenterOfMass: (%f, %f)\n", centerOfMass.X, centerOfMass.Y) - - return centerOfMass -} - -// genForestTree generates a forest representation of the tree with the given index -func GenForestTree(database *sql.DB, index int64) string { - db = database - rootNodeID := getRootNodeID(index) - return genForestTreeNode(rootNodeID) -} - -// genForestTreeNodes returns a sub-representation of a given node in forest format -func genForestTreeNode(nodeID int64) string { - var returnString string - - // get the subnode ids - var subnode [4]int64 - - query := fmt.Sprintf("SELECT subnode[1], subnode[2], subnode[3], subnode[4] FROM nodes WHERE node_id=%d", nodeID) - err := db.QueryRow(query).Scan(&subnode[0], &subnode[1], &subnode[2], &subnode[3]) - if err != nil { - log.Fatalf("[ E ] updateTotalMassNode query: %v\n\t\t\t query: %s\n", err, query) - } - - returnString += "[" - - // iterate over all subnodes updating their total masses - for _, subnodeID := range subnode { - if subnodeID != 0 { - centerOfMass := getCenterOfMass(nodeID) - mass := getNodeTotalMass(nodeID) - returnString += fmt.Sprintf("%.0f %.0f %.0f", centerOfMass.X, centerOfMass.Y, mass) - returnString += genForestTreeNode(subnodeID) - } else { - if getStarID(nodeID) != 0 { - coords := getStarCoordinates(nodeID) - starID := getStarID(nodeID) - mass := getStarMass(starID) - returnString += fmt.Sprintf("[%.0f %.0f %.0f]", coords.X, coords.Y, mass) - } else { - returnString += fmt.Sprintf("[0 0]") - } - // break, this stops a star from being counted multiple (4) times - break - } - } - - returnString += "]" - - return returnString -} - -// getCenterOfMass returns the center of mass of the given nodeID -func getCenterOfMass(nodeID int64) structs.Vec2 { - - var CenterOfMass [2]float64 - - // get the star from the stars table - query := fmt.Sprintf("SELECT center_of_mass[1], center_of_mass[2] FROM nodes WHERE node_id=%d", nodeID) - err := db.QueryRow(query).Scan(&CenterOfMass[0], &CenterOfMass[1]) - if err != nil { - log.Fatalf("[ E ] getCenterOfMass query: %v \n\t\t\tquery: %s\n", err, query) - } - - return structs.Vec2{X: CenterOfMass[0], Y: CenterOfMass[1]} -} - -// getStarCoordinates gets the star coordinates of a star using a given nodeID. It returns a vector describing the -// coordinates -func getStarCoordinates(nodeID int64) structs.Vec2 { - var Coordinates [2]float64 - - starID := getStarID(nodeID) - - // get the star from the stars table - query := fmt.Sprintf("SELECT x, y FROM stars WHERE star_id=%d", starID) - err := db.QueryRow(query).Scan(&Coordinates[0], &Coordinates[1]) - if err != nil { - log.Fatalf("[ E ] getStarCoordinates query: %v \n\t\t\tquery: %s\n", err, query) - } - - fmt.Printf("%v\n", Coordinates) - - return structs.Vec2{X: Coordinates[0], Y: Coordinates[1]} -} -- cgit 1.4.1