Initial commit

node_modules/@maplibre/mlt/dist/metadata/tile/streamMetadataDecoder.js

@@ -0,0 +1,91 @@
+import { LogicalLevelTechnique } from "./logicalLevelTechnique";
+import { PhysicalLevelTechnique } from "./physicalLevelTechnique";
+import { decodeVarintInt32 } from "../../decoding/integerDecodingUtils";
+import { PhysicalStreamType } from "./physicalStreamType";
+import { DictionaryType } from "./dictionaryType";
+import { OffsetType } from "./offsetType";
+import { LengthType } from "./lengthType";
+export function decodeStreamMetadata(tile, offset) {
+    const streamMetadata = decodeStreamMetadataInternal(tile, offset);
+    if (streamMetadata.logicalLevelTechnique1 === LogicalLevelTechnique.MORTON) {
+        return decodePartialMortonEncodedStreamMetadata(streamMetadata, tile, offset);
+    }
+    if ((LogicalLevelTechnique.RLE === streamMetadata.logicalLevelTechnique1 ||
+        LogicalLevelTechnique.RLE === streamMetadata.logicalLevelTechnique2) &&
+        PhysicalLevelTechnique.NONE !== streamMetadata.physicalLevelTechnique) {
+        return decodePartialRleEncodedStreamMetadata(streamMetadata, tile, offset);
+    }
+    return streamMetadata;
+}
+function decodePartialMortonEncodedStreamMetadata(streamMetadata, tile, offset) {
+    const mortonInfo = decodeVarintInt32(tile, offset, 2);
+    return {
+        physicalStreamType: streamMetadata.physicalStreamType,
+        logicalStreamType: streamMetadata.logicalStreamType,
+        logicalLevelTechnique1: streamMetadata.logicalLevelTechnique1,
+        logicalLevelTechnique2: streamMetadata.logicalLevelTechnique2,
+        physicalLevelTechnique: streamMetadata.physicalLevelTechnique,
+        numValues: streamMetadata.numValues,
+        byteLength: streamMetadata.byteLength,
+        decompressedCount: streamMetadata.decompressedCount,
+        numBits: mortonInfo[0],
+        coordinateShift: mortonInfo[1],
+    };
+}
+function decodePartialRleEncodedStreamMetadata(streamMetadata, tile, offset) {
+    const rleInfo = decodeVarintInt32(tile, offset, 2);
+    return {
+        physicalStreamType: streamMetadata.physicalStreamType,
+        logicalStreamType: streamMetadata.logicalStreamType,
+        logicalLevelTechnique1: streamMetadata.logicalLevelTechnique1,
+        logicalLevelTechnique2: streamMetadata.logicalLevelTechnique2,
+        physicalLevelTechnique: streamMetadata.physicalLevelTechnique,
+        numValues: streamMetadata.numValues,
+        byteLength: streamMetadata.byteLength,
+        decompressedCount: rleInfo[1],
+        runs: rleInfo[0],
+        numRleValues: rleInfo[1],
+    };
+}
+function decodeStreamMetadataInternal(tile, offset) {
+    const stream_type = tile[offset.get()];
+    const physicalStreamType = Object.values(PhysicalStreamType)[stream_type >> 4];
+    let logicalStreamType = null;
+    switch (physicalStreamType) {
+        case PhysicalStreamType.DATA:
+            logicalStreamType = {
+                dictionaryType: Object.values(DictionaryType)[stream_type & 0xf],
+            };
+            break;
+        case PhysicalStreamType.OFFSET:
+            logicalStreamType = {
+                offsetType: Object.values(OffsetType)[stream_type & 0xf],
+            };
+            break;
+        case PhysicalStreamType.LENGTH:
+            logicalStreamType = {
+                lengthType: Object.values(LengthType)[stream_type & 0xf],
+            };
+            break;
+    }
+    offset.increment();
+    const encodings_header = tile[offset.get()];
+    const llt1 = Object.values(LogicalLevelTechnique)[encodings_header >> 5];
+    const llt2 = Object.values(LogicalLevelTechnique)[(encodings_header >> 2) & 0x7];
+    const plt = Object.values(PhysicalLevelTechnique)[encodings_header & 0x3];
+    offset.increment();
+    const sizeInfo = decodeVarintInt32(tile, offset, 2);
+    const numValues = sizeInfo[0];
+    const byteLength = sizeInfo[1];
+    return {
+        physicalStreamType,
+        logicalStreamType,
+        logicalLevelTechnique1: llt1,
+        logicalLevelTechnique2: llt2,
+        physicalLevelTechnique: plt,
+        numValues,
+        byteLength,
+        decompressedCount: numValues,
+    };
+}
+//# sourceMappingURL=streamMetadataDecoder.js.map