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Remove duplication
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@bchapuis
bchapuis committed Jan 11, 2025
1 parent a933b6d commit edbe365
Showing 1 changed file with 54 additions and 120 deletions.
174 changes: 54 additions & 120 deletions baremaps-core/src/main/java/org/apache/baremaps/tilestore/postgres/PostgresTileStore.java
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Original file line number Diff line number Diff line change
Expand Up @@ -127,22 +127,8 @@ public ByteBuffer read(TileCoord tileCoord) throws TileStoreException {
* @param zoom the zoom level
* @return the prepared query
*/
protected Query prepareQuery(int zoom) {
if (postgresVersion >= 16) {
return prepareNewQuery(zoom);
} else {
return prepareLegacyQuery(zoom);
}
}

/**
* Prepare the sql query for a given zoom level that uses the new version of postgresql (>= 16).
*
* @param zoom the zoom level
* @return the prepared query
*/
@SuppressWarnings("squid:S3776")
private Query prepareNewQuery(int zoom) {
protected Query prepareQuery(int zoom) {
// Initialize a builder for the tile sql
var tileSql = new StringBuilder();
tileSql.append("SELECT ");
Expand Down Expand Up @@ -179,17 +165,10 @@ private Query prepareNewQuery(int zoom) {
.replace(";", "")
.replace("?", "??")
.replace("$zoom", String.valueOf(zoom));
var querySqlWithParams = String.format(
"""
SELECT
mvtData.id AS id,
mvtData.tags - 'id' AS tags,
ST_AsMVTGeom(mvtData.geom, ST_TileEnvelope(?, ?, ?)) AS geom
FROM (%s) AS mvtData
WHERE mvtData.geom IS NOT NULL
AND mvtData.geom && ST_TileEnvelope(?, ?, ?, margin => (64.0/4096))
""",
querySql);

var querySqlWithParams =
postgresVersion >= 16 ? prepareNewQuery(querySql) : prepareLegacyQuery(querySql);

layerSql.append(querySqlWithParams);

// Increase the parameter count (e.g. ?) and sql count
Expand Down Expand Up @@ -223,113 +202,68 @@ AND mvtData.geom && ST_TileEnvelope(?, ?, ?, margin => (64.0/4096))
tileSql.append(tileQueryTail);

// Format the sql query
var sql = tileSql.toString().replace("\n", " ");
var sql = tileSql.toString().replaceAll("\\s+", " ");

return new Query(sql, paramCount);
}

/**
* Prepare the sql query for a given zoom level that uses the legacy versions of postgresql (<
* 16).
* Prepare the sql query for the new versions of postgresql (>= 16).
* <p>
* Recent versions of the postgresql database better optimize subqueries. Using subqueries is more
* robust and allows for more complex queries.
*
* @param zoom the zoom level
* @param sql the sql query
* @return the prepared query
*/
@SuppressWarnings("squid:S3776")
private Query prepareLegacyQuery(int zoom) {
// Initialize a builder for the tile sql
var tileSql = new StringBuilder();
tileSql.append("SELECT ");

// Iterate over the layers and keep track of the number of layers and parameters included in the
// final sql
var layers = tileset.getVectorLayers();
var layerCount = 0;
var paramCount = 0;
for (var layer : layers) {

// Initialize a builder for the layer sql
var layerSql = new StringBuilder();
var layerHead = String.format("(SELECT ST_AsMVT(mvtGeom.*, '%s') FROM (", layer.getId());
layerSql.append(layerHead);

// Iterate over the queries and keep track of the number of queries included in the final
// sql
var queries = layer.getQueries();
var queryCount = 0;
for (var query : queries) {

// Only include the sql if the zoom level is in the range
if (query.getMinzoom() <= zoom && zoom < query.getMaxzoom()) {

// Add a union between queries
if (queryCount > 0) {
layerSql.append("UNION ALL ");
}

// Add the sql to the layer sql
var querySql = query.getSql().trim()
.replaceAll("\\s+", " ")
.replace(";", "")
.replace("?", "??")
.replace("$zoom", String.valueOf(zoom));

// Append a new condition or a where clause
if (querySql.toLowerCase().contains("where")) {
querySql += " AND ";
} else {
querySql += " WHERE ";
}

// Append the condition to the query sql
querySql +=
"geom IS NOT NULL AND geom && ST_TileEnvelope(?, ?, ?, margin => (64.0/4096))";

var querySqlWithParams = String.format(
"""
SELECT
mvtData.id AS id,
mvtData.tags - 'id' AS tags,
ST_AsMVTGeom(mvtData.geom, ST_TileEnvelope(?, ?, ?)) AS geom
FROM (%s) as mvtData
""",
querySql);
layerSql.append(querySqlWithParams);

// Increase the parameter count (e.g. ?) and sql count
paramCount += 6;
queryCount++;
}
}

// Add the tail of the layer sql
var layerQueryTail = ") AS mvtGeom)";
layerSql.append(layerQueryTail);

// Only include the layer sql if queries were included for this layer
if (queryCount > 0) {

// Add the concatenation between layer queries
if (layerCount > 0) {
tileSql.append(" || ");
}
private String prepareNewQuery(final String sql) {
return String.format(
"""
SELECT
mvtData.id AS id,
mvtData.tags - 'id' AS tags,
ST_AsMVTGeom(mvtData.geom, ST_TileEnvelope(?, ?, ?)) AS geom
FROM (%s) AS mvtData
WHERE mvtData.geom IS NOT NULL
AND mvtData.geom && ST_TileEnvelope(?, ?, ?, margin => (64.0/4096))
""",
sql);
}

// Add the layer sql to the mvt sql
tileSql.append(layerSql);
/**
* Prepare the sql query for the legacy versions of postgresql (< 16).
* <p>
* Older versions of the postgresql database do not optimize subqueries. Therefore, the conditions
* are appended to the sql query, which is less robust and error-prone.
*
* @param sql the sql query
* @return the prepared query
*/
@SuppressWarnings("squid:S3776")
private String prepareLegacyQuery(final String sql) {
String query = sql;

// Increase the layer count
layerCount++;
}
// Append a new condition or a where clause
if (sql.toLowerCase().contains("where")) {
query += " AND ";
} else {
query += " WHERE ";
}

// Add the tail of the tile sql
var tileQueryTail = " AS mvtTile";
tileSql.append(tileQueryTail);

// Format the sql query
var sql = tileSql.toString().replaceAll("\\s+", " ");

return new Query(sql, paramCount);
// Append the condition to the query sql
query +=
"geom IS NOT NULL AND geom && ST_TileEnvelope(?, ?, ?, margin => (64.0/4096))";

return String.format(
"""
SELECT
mvtData.id AS id,
mvtData.tags - 'id' AS tags,
ST_AsMVTGeom(mvtData.geom, ST_TileEnvelope(?, ?, ?)) AS geom
FROM (%s) as mvtData
""",
query);
}

/**
Expand Down

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