@foxglove/ulog/dist/parse.js

PX4 ULog file reader

"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
exports.parseMessage = parseMessage;
exports.parseFieldValue = parseFieldValue;
exports.parseBasicFieldValue = parseBasicFieldValue;
exports.messageSize = messageSize;
exports.fieldSize = fieldSize;
const BASIC_PARSERS = {
    bool: (view, offset) => view.getUint8(offset) !== 0,
    int8_t: (view, offset) => view.getInt8(offset),
    uint8_t: (view, offset) => view.getUint8(offset),
    int16_t: (view, offset) => view.getInt16(offset, true),
    uint16_t: (view, offset) => view.getUint16(offset, true),
    int32_t: (view, offset) => view.getInt32(offset, true),
    uint32_t: (view, offset) => view.getUint32(offset, true),
    int64_t: (view, offset) => view.getBigInt64(offset, true),
    uint64_t: (view, offset) => view.getBigUint64(offset, true),
    float: (view, offset) => view.getFloat32(offset, true),
    double: (view, offset) => view.getFloat64(offset, true),
    char: (view, offset) => String.fromCharCode(view.getUint8(offset)),
};
const BASIC_SIZES = {
    bool: 1,
    int8_t: 1,
    uint8_t: 1,
    int16_t: 2,
    uint16_t: 2,
    int32_t: 4,
    uint32_t: 4,
    int64_t: 8,
    uint64_t: 8,
    float: 4,
    double: 8,
    char: 1,
};
const textDecoder = new TextDecoder();
function parseMessage(definition, definitions, view, offset = 0) {
    const output = {};
    let curOffset = offset;
    for (const field of definition.fields) {
        if (!field.name.startsWith("_")) {
            output[field.name] = parseFieldValue(field, definitions, view, curOffset);
        }
        curOffset += fieldSize(field, definitions) * (field.arrayLength ?? 1);
    }
    if (typeof output.timestamp !== "bigint") {
        throw new Error(`Message "${definition.name}" is missing a timestamp field`);
    }
    return output;
}
function parseFieldValue(field, definitions, view, offset = 0) {
    if (field.isComplex) {
        const definition = definitions.get(field.type);
        if (!definition) {
            throw new Error(`Unknown type ${field.type}, searched ${definitions.size} definitions`);
        }
        if (field.arrayLength != undefined) {
            const size = fieldSize(field, definitions);
            const output = new Array(field.arrayLength);
            for (let i = 0; i < field.arrayLength; i++) {
                output[i] = parseMessage(definition, definitions, view, offset + i * size);
            }
            return output;
        }
        return parseMessage(definition, definitions, view, offset);
    }
    return parseBasicFieldValue(field, view, offset);
}
function parseBasicFieldValue(field, view, offset = 0) {
    const basicType = field.type;
    const parser = BASIC_PARSERS[basicType];
    if (field.arrayLength != undefined) {
        // String handling
        if (field.type === "char") {
            const len = Math.min(field.arrayLength, view.byteLength - offset);
            const byteOffset = view.byteOffset + offset;
            return textDecoder.decode(new Uint8Array(view.buffer, byteOffset, len));
        }
        const basicSize = BASIC_SIZES[basicType];
        const output = new Array(field.arrayLength);
        for (let i = 0; i < field.arrayLength; i++) {
            output[i] = parser(view, offset + i * basicSize);
        }
        return output;
    }
    return parser(view, offset);
}
function messageSize(definition, definitions) {
    return definition.fields.reduce((size, f) => size + fieldSize(f, definitions) * (f.arrayLength ?? 1), 0);
}
function fieldSize(field, definitions) {
    if (field.size != undefined) {
        return field.size;
    }
    if (field.isComplex) {
        const definition = definitions.get(field.type);
        if (!definition) {
            throw new Error(`Unknown type ${field.type}, searched ${definitions.size} definitions`);
        }
        field.size = messageSize(definition, definitions);
    }
    else {
        field.size = BASIC_SIZES[field.type];
    }
    return field.size;
}
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