How to save PDF Byte Array In to MongoDb Using c# ?

From a performance perspective, saving and retrieving the file in binary form is faster than first serializing it to a string. In a test program, running against a MongoDb 3.2 database, saving a file in binary form in a document was up to 3 times faster than saving the file in a string-serialized form. Which is understandable, since the string-serialized form is simply 'more bytes' to save or read.

In the same test program a quick test was also performed against GridFS, but there you really have to play a round with the chunck-size to get to the best possible performance.

class Program
{
static bool keepRunning;
static string fileName = "example.jpg";
static int numDocs = 571;
static IMongoDatabase mongoDb;
static void Main(string[] args)
{
Console.CancelKeyPress += delegate
{
Exit();
};
keepRunning = true;
SetupMongoDb();
var fileBytes = File.ReadAllBytes(fileName);
Console.WriteLine($"Picturesize in bytes: {fileBytes.Length}");
ClearCollections();
Console.WriteLine($"Saving {numDocs} pictures to the database.");
Console.WriteLine("\nStart Saving in Binary Mode.");
Stopwatch binaryStopWatch = Stopwatch.StartNew();
SaveBinaryBased(numDocs, fileBytes);
binaryStopWatch.Stop();
Console.WriteLine("Done Saving in Binary Mode.");
Console.WriteLine("\nStart Saving in String-based Mode.");
Stopwatch stringStopWatch = Stopwatch.StartNew();
SaveStringBased(numDocs, fileBytes);
stringStopWatch.Stop();
Console.WriteLine("Done Saving in String-based Mode.");
Console.WriteLine("\nTime Report Saving");
Console.WriteLine($" * Total Time Binary for {numDocs} records: {binaryStopWatch.ElapsedMilliseconds} ms.");
Console.WriteLine($" * Total Time String for {numDocs} records: {stringStopWatch.ElapsedMilliseconds} ms.");
Console.WriteLine("\nCollection Statistics:");
Statistics("binaryPics");
Statistics("stringBasedPics");
Console.WriteLine("\nTest Retrieval:");
Console.WriteLine("\nStart Retrieving from binary collection.");
binaryStopWatch.Restart();
RetrieveBinary();
binaryStopWatch.Stop();
Console.WriteLine("Done Retrieving from binary collection.");
Console.WriteLine("\nStart Retrieving from string-based collection.");
stringStopWatch.Restart();
RetrieveString();
stringStopWatch.Stop();
Console.WriteLine("Done Retrieving from string-based collection.");
Console.WriteLine("\nTime Report Retrieving:");
Console.WriteLine($" * Total Time Binary for retrieving {numDocs} records: {binaryStopWatch.ElapsedMilliseconds} ms.");
Console.WriteLine($" * Total Time String for retrieving {numDocs} records: {stringStopWatch.ElapsedMilliseconds} ms.");
ClearGridFS();
Console.WriteLine($"\nStart saving {numDocs} files to GridFS:");
binaryStopWatch.Restart();
SaveFilesToGridFS(numDocs, fileBytes);
binaryStopWatch.Stop();
Console.WriteLine($"Saved {numDocs} files to GridFS in {binaryStopWatch.ElapsedMilliseconds} ms.");
Console.WriteLine($"\nStart retrieving {numDocs} files from GridFS:");
binaryStopWatch.Restart();
RetrieveFromGridFS();
binaryStopWatch.Stop();
Console.WriteLine($"Retrieved {numDocs} files from GridFS in {binaryStopWatch.ElapsedMilliseconds} ms.");
while (keepRunning)
{
Thread.Sleep(500);
}
}
private static void Exit()
{
keepRunning = false;
}
private static void ClearCollections()
{
var collectionBin = mongoDb.GetCollection("binaryPics");
var collectionString = mongoDb.GetCollection("stringBasedPics");
collectionBin.DeleteMany(new BsonDocument());
collectionString.DeleteMany(new BsonDocument());
}
private static void SetupMongoDb()
{
string hostName = "localhost";
int portNumber = 27017;
string databaseName = "exampleSerialization";
var clientSettings = new MongoClientSettings()
{
Server = new MongoServerAddress(hostName, portNumber),
MinConnectionPoolSize = 1,
MaxConnectionPoolSize = 1500,
ConnectTimeout = new TimeSpan(0, 0, 30),
SocketTimeout = new TimeSpan(0, 1, 30),
WaitQueueTimeout = new TimeSpan(0, 1, 0)
};
mongoDb = new MongoClient(clientSettings).GetDatabase(databaseName);
}
private static void SaveBinaryBased(int numDocuments, byte[] content)
{
var collection = mongoDb.GetCollection("binaryPics");
BsonDocument baseDoc = new BsonDocument();
baseDoc.SetElement(new BsonElement("jpgContent", content));
for (int i = 0; i < numDocs; ++i)
{
baseDoc.SetElement(new BsonElement("_id", Guid.NewGuid()));
baseDoc.SetElement(new BsonElement("filename", fileName));
baseDoc.SetElement(new BsonElement("title", $"picture number {i}"));
collection.InsertOne(baseDoc);
}
}
private static void SaveStringBased(int numDocuments, byte[] content)
{
var collection = mongoDb.GetCollection("stringBasedPics");
BsonDocument baseDoc = new BsonDocument();
baseDoc.SetElement(new BsonElement("jpgStringContent", System.Text.Encoding.UTF8.GetString(content)));
for (int i = 0; i < numDocs; ++i)
{
baseDoc.SetElement(new BsonElement("_id", Guid.NewGuid()));
baseDoc.SetElement(new BsonElement("filename", fileName));
baseDoc.SetElement(new BsonElement("title", $"picture number {i}"));
collection.InsertOne(baseDoc);
}
}
private static void Statistics(string collectionName)
{
new BsonDocument { { "collstats", collectionName } };
var command = new BsonDocumentCommand(new BsonDocument { { "collstats", collectionName } });
var stats = mongoDb.RunCommand(command);
Console.WriteLine($" * Collection : {collectionName}");
Console.WriteLine($" * Count : {stats["count"].AsInt32} documents");
Console.WriteLine($" * Average Doc Size: {stats["avgObjSize"].AsInt32} bytes");
Console.WriteLine($" * Total Storage : {stats["storageSize"].AsInt32} bytes");
Console.WriteLine("\n");
}
private static void RetrieveBinary()
{
var collection = mongoDb.GetCollection("binaryPics");
var docs = collection.Find(new BsonDocument()).ToEnumerable();
foreach (var doc in docs)
{
byte[] fileArray = doc.GetElement("jpgContent").Value.AsByteArray;
// we can simulate that we do something with the results but that's not the purpose of this experiment
fileArray = null;
}
}
private static void RetrieveString()
{
var collection = mongoDb.GetCollection("stringBasedPics");
var docs = collection.Find(new BsonDocument()).ToEnumerable();
foreach (var doc in docs)
{
// Simply get the string, we don't want to hit the performance test
// with a conversion to a byte array
string result = doc.GetElement("jpgStringContent").Value.AsString;
}
}
private static void SaveFilesToGridFS(int numFiles, byte[] content)
{
var bucket = new GridFSBucket(mongoDb, new GridFSBucketOptions
{
BucketName = "pictures"
});
for (int i = 0; i < numFiles; ++i)
{
string targetFileName = $"{fileName.Substring(0, fileName.Length - ".jpg".Length)}{i}.jpg";
int chunkSize = content.Length <= 1048576 ? 51200 : 1048576;
bucket.UploadFromBytes(targetFileName, content, new GridFSUploadOptions { ChunkSizeBytes = chunkSize });
}
}
private static void ClearGridFS()
{
var bucket = new GridFSBucket(mongoDb, new GridFSBucketOptions { BucketName = "pictures" });
bucket.Drop();
}
private static void RetrieveFromGridFS()
{
var bucket = new GridFSBucket(mongoDb, new GridFSBucketOptions { BucketName = "pictures" });
var filesIds = mongoDb.GetCollection("pictures.files").Find(new BsonDocument()).ToEnumerable().Select(doc => doc.GetElement("_id").Value);
foreach (var id in filesIds)
{
var fileBytes = bucket.DownloadAsBytes(id);
fileBytes = null;
}
}
}

1 Reply

Know the answer? Post it — somebody with the same question will find it here.

Gokhul Varman9y ago
From a performance perspective, saving and retrieving the file in binary form is faster than first serializing it to a string. In a test program, running against a MongoDb 3.2 database, saving a file in binary form in a document was up to 3 times faster than saving the file in a string-serialized form. Which is understandable, since the string-serialized form is simply 'more bytes' to save or read.
In the same test program a quick test was also performed against GridFS, but there you really have to play a round with the chunck-size to get to the best possible performance.
class Program
{
    static bool keepRunning;
    static string fileName = "example.jpg";
    static int numDocs = 571;
    static IMongoDatabase mongoDb;

    static void Main(string[] args)
    {
        Console.CancelKeyPress += delegate
        {
            Exit();
        };

        keepRunning = true;

        SetupMongoDb();

        var fileBytes = File.ReadAllBytes(fileName);
        Console.WriteLine($"Picturesize in bytes: {fileBytes.Length}");

        ClearCollections();

        Console.WriteLine($"Saving {numDocs} pictures to the database.");

        Console.WriteLine("\nStart Saving in Binary Mode.");
        Stopwatch binaryStopWatch = Stopwatch.StartNew();
        SaveBinaryBased(numDocs, fileBytes);
        binaryStopWatch.Stop();
        Console.WriteLine("Done Saving in Binary Mode.");

        Console.WriteLine("\nStart Saving in String-based Mode.");
        Stopwatch stringStopWatch = Stopwatch.StartNew();
        SaveStringBased(numDocs, fileBytes);
        stringStopWatch.Stop();
        Console.WriteLine("Done Saving in String-based Mode.");

        Console.WriteLine("\nTime Report Saving");
        Console.WriteLine($"   * Total Time Binary for {numDocs} records: {binaryStopWatch.ElapsedMilliseconds} ms.");
        Console.WriteLine($"   * Total Time String for {numDocs} records: {stringStopWatch.ElapsedMilliseconds} ms.");

        Console.WriteLine("\nCollection Statistics:");
        Statistics("binaryPics");
        Statistics("stringBasedPics");

        Console.WriteLine("\nTest Retrieval:");
        Console.WriteLine("\nStart Retrieving from binary collection.");
        binaryStopWatch.Restart();
        RetrieveBinary();
        binaryStopWatch.Stop();
        Console.WriteLine("Done Retrieving from binary collection.");

        Console.WriteLine("\nStart Retrieving from string-based collection.");
        stringStopWatch.Restart();
        RetrieveString();
        stringStopWatch.Stop();
        Console.WriteLine("Done Retrieving from string-based collection.");

        Console.WriteLine("\nTime Report Retrieving:");
        Console.WriteLine($"   * Total Time Binary for retrieving {numDocs} records: {binaryStopWatch.ElapsedMilliseconds} ms.");
        Console.WriteLine($"   * Total Time String for retrieving {numDocs} records: {stringStopWatch.ElapsedMilliseconds} ms.");

        ClearGridFS();
        Console.WriteLine($"\nStart saving {numDocs} files to GridFS:");
        binaryStopWatch.Restart();
        SaveFilesToGridFS(numDocs, fileBytes);
        binaryStopWatch.Stop();
        Console.WriteLine($"Saved {numDocs} files to GridFS in {binaryStopWatch.ElapsedMilliseconds} ms.");

        Console.WriteLine($"\nStart retrieving {numDocs} files from GridFS:");
        binaryStopWatch.Restart();
        RetrieveFromGridFS();
        binaryStopWatch.Stop();
        Console.WriteLine($"Retrieved {numDocs} files from GridFS in {binaryStopWatch.ElapsedMilliseconds} ms.");

        while (keepRunning)
        {
            Thread.Sleep(500);
        }
    }

    private static void Exit()
    {
        keepRunning = false;
    }

    private static void ClearCollections()
    {
        var collectionBin = mongoDb.GetCollection("binaryPics");
        var collectionString = mongoDb.GetCollection("stringBasedPics");

        collectionBin.DeleteMany(new BsonDocument());
        collectionString.DeleteMany(new BsonDocument());
    }

    private static void SetupMongoDb()
    {
        string hostName = "localhost";
        int portNumber = 27017;
        string databaseName = "exampleSerialization";

        var clientSettings = new MongoClientSettings()
        {
            Server = new MongoServerAddress(hostName, portNumber),
            MinConnectionPoolSize = 1,
            MaxConnectionPoolSize = 1500,
            ConnectTimeout = new TimeSpan(0, 0, 30),
            SocketTimeout = new TimeSpan(0, 1, 30),
            WaitQueueTimeout = new TimeSpan(0, 1, 0)
        };

        mongoDb = new MongoClient(clientSettings).GetDatabase(databaseName);
    }

    private static void SaveBinaryBased(int numDocuments, byte[] content)
    {
        var collection = mongoDb.GetCollection("binaryPics");

        BsonDocument baseDoc = new BsonDocument();
        baseDoc.SetElement(new BsonElement("jpgContent", content));

        for (int i = 0; i < numDocs; ++i)
        {
            baseDoc.SetElement(new BsonElement("_id", Guid.NewGuid()));
            baseDoc.SetElement(new BsonElement("filename", fileName));
            baseDoc.SetElement(new BsonElement("title", $"picture number {i}"));
            collection.InsertOne(baseDoc);
        }
    }

    private static void SaveStringBased(int numDocuments, byte[] content)
    {
        var collection = mongoDb.GetCollection("stringBasedPics");

        BsonDocument baseDoc = new BsonDocument();
        baseDoc.SetElement(new BsonElement("jpgStringContent", System.Text.Encoding.UTF8.GetString(content)));

        for (int i = 0; i < numDocs; ++i)
        {
            baseDoc.SetElement(new BsonElement("_id", Guid.NewGuid()));
            baseDoc.SetElement(new BsonElement("filename", fileName));
            baseDoc.SetElement(new BsonElement("title", $"picture number {i}"));
            collection.InsertOne(baseDoc);
        }
    }

    private static void Statistics(string collectionName)
    {
        new BsonDocument { { "collstats", collectionName } };
        var command = new BsonDocumentCommand(new BsonDocument { { "collstats", collectionName } });
        var stats = mongoDb.RunCommand(command);

        Console.WriteLine($"  * Collection      : {collectionName}");
        Console.WriteLine($"  * Count           : {stats["count"].AsInt32} documents");
        Console.WriteLine($"  * Average Doc Size: {stats["avgObjSize"].AsInt32} bytes");
        Console.WriteLine($"  * Total Storage   : {stats["storageSize"].AsInt32} bytes");
        Console.WriteLine("\n");
    }

    private static void RetrieveBinary()
    {
        var collection = mongoDb.GetCollection("binaryPics");
        var docs = collection.Find(new BsonDocument()).ToEnumerable();

        foreach (var doc in docs)
        {
            byte[] fileArray = doc.GetElement("jpgContent").Value.AsByteArray;
            // we can simulate that we do something with the results but that's not the purpose of this experiment
            fileArray = null;
        }
    }

    private static void RetrieveString()
    {
        var collection = mongoDb.GetCollection("stringBasedPics");
        var docs = collection.Find(new BsonDocument()).ToEnumerable();

        foreach (var doc in docs)
        {
            // Simply get the string, we don't want to hit the performance test
            // with a conversion to a byte array
            string result = doc.GetElement("jpgStringContent").Value.AsString;
        }
    }

    private static void SaveFilesToGridFS(int numFiles, byte[] content)
    {
        var bucket = new GridFSBucket(mongoDb, new GridFSBucketOptions
        {
            BucketName = "pictures"
        });

        for (int i = 0; i < numFiles; ++i)
        {
            string targetFileName = $"{fileName.Substring(0, fileName.Length - ".jpg".Length)}{i}.jpg";
            int chunkSize = content.Length <= 1048576 ? 51200 : 1048576;
            bucket.UploadFromBytes(targetFileName, content, new GridFSUploadOptions { ChunkSizeBytes = chunkSize });
        }
    }

    private static void ClearGridFS()
    {
        var bucket = new GridFSBucket(mongoDb, new GridFSBucketOptions { BucketName = "pictures" });
        bucket.Drop();
    }

    private static void RetrieveFromGridFS()
    {
        var bucket = new GridFSBucket(mongoDb, new GridFSBucketOptions { BucketName = "pictures" });
        var filesIds = mongoDb.GetCollection("pictures.files").Find(new BsonDocument()).ToEnumerable().Select(doc => doc.GetElement("_id").Value);

        foreach (var id in filesIds)
        {
            var fileBytes = bucket.DownloadAsBytes(id);
            fileBytes = null;
        }
    }
}
0