@sap/xsodata/lib/utils/batch/batchParser.js

Expose data from a HANA database as OData V2 service with help of .xsodata files.

'use strict';

var utils = require('./../utils');
var batchObjects = require('./batchObjects');

exports.getBoundary = function (headerValue) {
    var l = headerValue.split(';');

    for (var i = 0; i < l.length; i++) {
        var ll = l[i].split('=');
        if (ll[0].trim() === 'boundary') {
            return ll[1];
        }
    }
};


function readAppHttp(batchContent, boundary) {
    var headers = {};
    var payload = [];

    var state = 0; //read url
    var url = batchContent.readLine();

    state = 1; //read header
    var line = batchContent.lookLine();

    while ((line !== null && line !== undefined) && line.indexOf(boundary) !== 0) {
        if (state === 1) {
            if (line.length === 0) {
                state = 2; //read body
                batchContent.inc();
            } else {
                var h = readHeader(line);
                headers[h.name] = h.value;
                batchContent.inc();
            }
        } else if (state === 2) {
            payload.push(line);
            batchContent.inc();
        }
        line = batchContent.lookLine();
    }
    if (line === undefined) {
        throw new Error("Invalid boundary while parsing batch request. Expect boundary " + boundary);
    }

    return new batchObjects.AppHttp(url, headers, payload);
}


function parsePart(batchContent, boundary) {
    var boundaryNext = boundary;
    var boundaryEnd = boundary + '--';
    var headers = {};
    var content;

    var state = 1; //read header
    var line = batchContent.lookLine();

    while ((line !== null && line !== undefined) && line !== boundaryNext && line !== boundaryEnd) {
        if (state === 1) {
            if (line.length === 0) {
                state = 2; //read body
                batchContent.inc();
            } else {
                var h = readHeader(line);
                headers[h.name] = h.value;
                batchContent.inc();
            }
        } else if (state === 2) {
            if (!headers['content-type']) {
                throw new Error('Missing header "content-type" in batch part');
            } else if (headers['content-type'] === 'application/http') {
                content = readAppHttp(batchContent, boundary);
            } else if (utils.startsWith(headers['content-type'], 'multipart/mixed;')) {
                var changeSetBoundary = exports.getBoundary(headers['content-type']);
                content = parseBatch(batchContent, changeSetBoundary, "changeset");
            } else {
                //TODO not supported
            }
        }
        line = batchContent.lookLine();
    }
    if (line === undefined) {
        throw new Error("Invalid boundary while parsing batch request. Expect boundary " + boundary);
    }

    return content;
    //return new batchObjects.BatchPart(headers, content);
}


function readHeader(line) {
    var colPos = line.indexOf(':');
    if (colPos === -1) {
        throw new Error('Invalid header "content-type" in batch part');
    }

    var s0 = line.substr(0, colPos);
    var s1 = line.substr(colPos + 1);
    return {
        name: s0.toLowerCase(),
        value: s1.trim()
    };
}

function parseBatch(content, boundary, type) {
    var boundaryNext = '--' + boundary;
    var boundaryEnd = '--' + boundary + '--';

    var batch = new batchObjects.Batch(type);

    var part;

    var line = content.readLine();
    while ((line !== null && line !== undefined) && line !== boundaryNext) { //read lines before first boundary
        line = content.readLine();
    }
    if (line === undefined) {
        throw new Error("Invalid boundary while parsing batch request");
    }
    //line is now read boundary
    line = content.lookLine(); //read line behind

    while ((line !== null && line !== undefined) && line !== boundaryEnd) {
        part = parsePart(content, boundaryNext);
        batch.parts.push(part);
        line = content.lookLine(); //now on boundary
        if (line === boundaryNext) {
            line = content.readLine();//consume boundaryNext
        }
    }

    content.readLine();//consume boundaryEnd
    line = content.lookLine(); //read line behind
    while ((line !== null && line !== undefined) && line.length === 0) { //read empty lines after first boundaryend
        content.readLine();
        line = content.lookLine();
    }

    return batch;
}


exports.convertBatch = function (payload, boundary) {
    return parseBatch(new batchObjects.BatchContent(payload), boundary, "batch");
};