C# Requires Chilkat v11.5.0+

Box: Upload a Large File in Parts and Commit the Session

See more Box Examples

Run the reusable setup once per HttpCurl object, then select names and execute the operation. The setup is repeated here only to make this published example independently runnable. Resolve documents by name, then perform the explicit chunked-upload session, part, and commit loop. Supports 20 MB through 2 GB using int. Saves recovery information and honors bounded commit Retry-After.

See the Box API guide for setup and the complete workflow.

C#

bool success = false;

//  Requires Chilkat 11.5.0 or later and a previously unlocked Chilkat bundle.
//  See Global Unlock Sample.
//  Guide: Box API Guide.

success = false;

//  BEGIN ONE-TIME SETUP
//  This block is repeated so each published example can run on its own.
//  In an application, run the setup example once and pass the SAME curl object
//  to operation code below. Do not recreate it for every operation.
//  See Reusable Box HttpCurl Setup.
Chilkat.HttpCurl curl = new Chilkat.HttpCurl();
curl.SetVar("access_token","BOX_ACCESS_TOKEN");
curl.SetVar("parent_name","/");
curl.SetVar("folder_name","images");
curl.SetVar("file_name","penguins.jpg");
curl.SetVar("destination_name","archive");
//  Box's fixed root ID is an implementation detail; callers supply names.
curl.SetVar("parent_id","0");
Chilkat.StringBuilder setupCommand = new Chilkat.StringBuilder();
int setupReplacements;

//  Register findParent; registration sends no request.
setupCommand.SetString("curl -X GET \"https://api.box.com/2.0/folders/0/items?limit=1000&fields=id,type,name\" -H \"Authorization: Bearer ACCESS_TOKEN\"");
setupReplacements = setupCommand.Replace("ACCESS_TOKEN",curl.GetVar("access_token"));
success = curl.AddFunction("findParent",setupCommand.GetAsString());
if (success != true) {
    Debug.WriteLine(curl.LastErrorText);
    return;
}

//  Register findFolder; registration sends no request.
setupCommand.SetString("curl -X GET \"https://api.box.com/2.0/folders/{{parent_id}}/items?limit=1000&fields=id,type,name\" -H \"Authorization: Bearer ACCESS_TOKEN\"");
setupReplacements = setupCommand.Replace("ACCESS_TOKEN",curl.GetVar("access_token"));
success = curl.AddFunction("findFolder",setupCommand.GetAsString());
if (success != true) {
    Debug.WriteLine(curl.LastErrorText);
    return;
}

//  Register findFile; registration sends no request.
setupCommand.SetString("curl -X GET \"https://api.box.com/2.0/folders/{{folder_id}}/items?limit=1000&fields=id,type,name\" -H \"Authorization: Bearer ACCESS_TOKEN\"");
setupReplacements = setupCommand.Replace("ACCESS_TOKEN",curl.GetVar("access_token"));
success = curl.AddFunction("findFile",setupCommand.GetAsString());
if (success != true) {
    Debug.WriteLine(curl.LastErrorText);
    return;
}

//  Register findDestination; registration sends no request.
setupCommand.SetString("curl -X GET \"https://api.box.com/2.0/folders/0/items?limit=1000&fields=id,type,name\" -H \"Authorization: Bearer ACCESS_TOKEN\"");
setupReplacements = setupCommand.Replace("ACCESS_TOKEN",curl.GetVar("access_token"));
success = curl.AddFunction("findDestination",setupCommand.GetAsString());
if (success != true) {
    Debug.WriteLine(curl.LastErrorText);
    return;
}

//  Register getFileDetails; registration sends no request.
setupCommand.SetString("curl -X GET \"https://api.box.com/2.0/files/{{file_id}}?fields=id,sha1,file_version\" -H \"Authorization: Bearer ACCESS_TOKEN\"");
setupReplacements = setupCommand.Replace("ACCESS_TOKEN",curl.GetVar("access_token"));
success = curl.AddFunction("getFileDetails",setupCommand.GetAsString());
if (success != true) {
    Debug.WriteLine(curl.LastErrorText);
    return;
}

//  Register getEnterprise; registration sends no request.
setupCommand.SetString("curl -X GET \"https://api.box.com/2.0/users/me?fields=enterprise\" -H \"Authorization: Bearer ACCESS_TOKEN\"");
setupReplacements = setupCommand.Replace("ACCESS_TOKEN",curl.GetVar("access_token"));
success = curl.AddFunction("getEnterprise",setupCommand.GetAsString());
if (success != true) {
    Debug.WriteLine(curl.LastErrorText);
    return;
}

//  Initial name selections. AddOutput2 stores these WHERE values literally.
success = curl.AddOutput2("findParent","entries","name",curl.GetVar("parent_name"),true,"id","parent_id");
if (success != true) {
    Debug.WriteLine(curl.LastErrorText);
    return;
}

success = curl.AddOutput2("findFolder","entries","name",curl.GetVar("folder_name"),true,"id","folder_id");
if (success != true) {
    Debug.WriteLine(curl.LastErrorText);
    return;
}

success = curl.AddOutput2("findFile","entries","name",curl.GetVar("file_name"),true,"id","file_id");
if (success != true) {
    Debug.WriteLine(curl.LastErrorText);
    return;
}

success = curl.AddOutput2("findDestination","entries","name",curl.GetVar("destination_name"),true,"id","destination_id");
if (success != true) {
    Debug.WriteLine(curl.LastErrorText);
    return;
}

success = curl.AddOutput("getFileDetails","file_version.id","file_version_id");
if (success != true) {
    Debug.WriteLine(curl.LastErrorText);
    return;
}

success = curl.AddOutput("getFileDetails","sha1","file_sha1");
if (success != true) {
    Debug.WriteLine(curl.LastErrorText);
    return;
}

success = curl.AddOutput("getEnterprise","enterprise.id","enterprise_id");
if (success != true) {
    Debug.WriteLine(curl.LastErrorText);
    return;
}

//  END ONE-TIME SETUP
//  The name lookups below assume each listing fits in one page (1000 items).
//  Parent and destination names select root children; folder_name selects a child
//  of parent_name. "/" selects the root parent. These are not arbitrary paths.

//  BEGIN OPERATION -- keep the configured object when reusing it.
//  Inputs are names. Retain cached IDs when the selected names have not changed.
string parentName = "/";
string folderName = "documents";
if ((curl.GetVar("parent_name") != parentName) || ((parentName == "/") && (curl.VarDefined("parent_id") == false))) {
    curl.SetVar("parent_name",parentName);
    curl.ClearVar("parent_id");
    curl.ClearVar("folder_id");
    curl.ClearVar("file_id");
    curl.ClearVar("file_version_id");
    curl.ClearVar("file_sha1");
    if (parentName == "/") {
        curl.SetVar("parent_id","0");
    }
    else {
        success = curl.AddOutput2("findParent","entries","name",curl.GetVar("parent_name"),true,"id","parent_id");
        if (success != true) {
            Debug.WriteLine(curl.LastErrorText);
            return;
        }

    }

}

if (curl.GetVar("folder_name") != folderName) {
    curl.SetVar("folder_name",folderName);
    curl.ClearVar("folder_id");
    curl.ClearVar("file_id");
    curl.ClearVar("file_version_id");
    curl.ClearVar("file_sha1");
    success = curl.AddOutput2("findFolder","entries","name",curl.GetVar("folder_name"),true,"id","folder_id");
    if (success != true) {
        Debug.WriteLine(curl.LastErrorText);
        return;
    }

}

//  Resolve the named destination first. HttpCurl does not expand variables
//  inside multipart -F attributes in the tested build, so this upload is two phases.
curl.ClearTargetOutput("*");
Chilkat.StringBuilder authorizedCommand1 = new Chilkat.StringBuilder();
authorizedCommand1.SetString("curl -X GET \"https://api.box.com/2.0/folders/{{folder_id}}?fields=id\" -H \"Authorization: Bearer {{access_token}}\"");
int headerReplacement1 = authorizedCommand1.Replace("{{access_token}}",curl.GetVar("access_token"));
success = curl.DoYourThing(authorizedCommand1.GetAsString());
if ((success != true) || (curl.StatusCode != 200)) {
    Debug.WriteLine("Box request failed. HTTP status: " + Convert.ToString(curl.StatusCode));
    Debug.WriteLine("Failure reason: " + Convert.ToString(curl.FailReason));
    Debug.WriteLine(curl.ResponseBodyStr);
    return;
}

//  This example limits size to 2 GB so offsets fit all generated languages' integers.
//  The source must not change during hashing or upload. Create qa_output first.
string localPath = "qa_data/large-document.zip";
Chilkat.FileAccess file = new Chilkat.FileAccess();
//  Check the decimal size before converting so an oversized file cannot overflow int.
string sizeString = file.FileSizeStr(localPath);
if (file.LastMethodSuccess != true) {
    Debug.WriteLine(file.LastErrorText);
    return;
}

Chilkat.StringBuilder sizeText = new Chilkat.StringBuilder();
sizeText.SetString(sizeString);
Chilkat.JsonObject sizeMatch = new Chilkat.JsonObject();
if (sizeText.RegexMatch("^([0-9]{1,9}|1[0-9]{9}|2000000000)$",sizeMatch,100) != 1) {
    Debug.WriteLine("Choose an input between 20 MB and 2 GB for this example.");
    return;
}

int fileSize = Convert.ToInt32(sizeString);
if (fileSize < 20971520) {
    Debug.WriteLine("Choose an input between 20 MB and 2 GB for this example.");
    return;
}

Chilkat.Http http = new Chilkat.Http();
http.AuthToken = curl.GetVar("access_token");
Chilkat.HttpResponse response = new Chilkat.HttpResponse();
Chilkat.JsonObject request = new Chilkat.JsonObject();
request.UpdateString("folder_id",curl.GetVar("folder_id"));
request.UpdateString("file_name","large-document.zip");
request.UpdateInt("file_size",fileSize);
success = http.HttpJson("POST","https://upload.box.com/api/2.0/files/upload_sessions",request,"application/json",response);
if (success != true) {
    Debug.WriteLine(http.LastErrorText);
    return;
}

if (response.StatusCode != 201) {
    Debug.WriteLine(response.BodyStr);
    return;
}

Chilkat.JsonObject session = new Chilkat.JsonObject();
success = session.Load(response.BodyStr);
if (success != true) {
    Debug.WriteLine(session.LastErrorText);
    return;
}

success = session.WriteFile("qa_output/box_upload_session.json");
if (success != true) {
    Debug.WriteLine(session.LastErrorText);
    return;
}

int partSize = session.IntOf("part_size");
string uploadUrl = session.StringOf("session_endpoints.upload_part");
string commitUrl = session.StringOf("session_endpoints.commit");
if ((partSize <= 0) || (uploadUrl == "") || (commitUrl == "")) {
    Debug.WriteLine("Invalid session response.");
    return;
}

Chilkat.Crypt2 hash = new Chilkat.Crypt2();
hash.HashAlgorithm = "sha1";
hash.EncodingMode = "base64";
string fileDigest = hash.HashFileENC(localPath);
if (hash.LastMethodSuccess != true) {
    Debug.WriteLine(hash.LastErrorText);
    return;
}

success = file.FileOpen(localPath,2147483648,1,3,0);
if (success != true) {
    Debug.WriteLine(file.LastErrorText);
    return;
}

Chilkat.JsonObject commit = new Chilkat.JsonObject();
Chilkat.JsonObject partResponse = new Chilkat.JsonObject();
Chilkat.BinData chunk = new Chilkat.BinData();
Chilkat.StringBuilder range = new Chilkat.StringBuilder();
Chilkat.StringBuilder digestHeader = new Chilkat.StringBuilder();
int offset = 0;
int partIndex = 0;
int partLength;
int lastByte;
string partDigest;
while (offset < fileSize) {
    chunk.Clear();
    success = file.FileReadBd(partSize,chunk);
    if (success != true) {
        Debug.WriteLine(file.LastErrorText);
        file.FileClose();
        return;
    }

    partLength = chunk.NumBytes;
    if (partLength <= 0) {
        Debug.WriteLine("Unexpected end of file.");
        file.FileClose();
        return;
    }

    lastByte = offset + (partLength - 1);
    range.Clear();
    range.Append("bytes ");
    range.AppendInt(offset);
    range.Append("-");
    range.AppendInt(lastByte);
    range.Append("/");
    range.AppendInt(fileSize);
    partDigest = hash.HashBdENC(chunk);
    if (hash.LastMethodSuccess != true) {
        Debug.WriteLine(hash.LastErrorText);
        file.FileClose();
        return;
    }

    digestHeader.SetString("sha=");
    digestHeader.Append(partDigest);
    http.SetRequestHeader("Digest",digestHeader.GetAsString());
    http.SetRequestHeader("Content-Range",range.GetAsString());
    success = http.HttpBd("PUT",uploadUrl,chunk,"application/octet-stream",response);
    if ((success != true) || (response.StatusCode != 200)) {
        Debug.WriteLine("Part failed. HTTP status: " + Convert.ToString(response.StatusCode));
        Debug.WriteLine(response.BodyStr);
        Debug.WriteLine("Inspect the saved session and server list_parts before retrying this part.");
        file.FileClose();
        return;
    }

    success = partResponse.Load(response.BodyStr);
    if (success != true) {
        file.FileClose();
        return;
    }

    commit.I = partIndex;
    //  Copy the server's acknowledged part fields into the commit manifest.
    commit.UpdateString("parts[i].part_id",partResponse.StringOf("part.part_id"));
    commit.UpdateInt("parts[i].offset",partResponse.IntOf("part.offset"));
    commit.UpdateInt("parts[i].size",partResponse.IntOf("part.size"));
    commit.UpdateString("parts[i].sha1",partResponse.StringOf("part.sha1"));
    success = commit.WriteFile("qa_output/box_upload_parts.json");
    if (success != true) {
        Debug.WriteLine(commit.LastErrorText);
        file.FileClose();
        return;
    }

    offset = offset + partLength;
    partIndex = partIndex + 1;
}

file.FileClose();
http.RemoveRequestHeader("Content-Range");
digestHeader.SetString("sha=");
digestHeader.Append(fileDigest);
http.SetRequestHeader("Digest",digestHeader.GetAsString());
int attempts = 0;
int waitSeconds;
Chilkat.StringBuilder retryHeader = new Chilkat.StringBuilder();
Chilkat.JsonObject retryMatch = new Chilkat.JsonObject();
bool completed = false;
while ((attempts < 10) && (completed == false)) {
    success = http.HttpJson("POST",commitUrl,commit,"application/json",response);
    if (success != true) {
        Debug.WriteLine("Commit failed: " + Convert.ToString(response.StatusCode));
        Debug.WriteLine(response.BodyStr);
        return;
    }

    if (response.StatusCode == 201) {
        completed = true;
    }
    else {
        if (response.StatusCode != 202) {
            Debug.WriteLine("Unexpected commit status: " + Convert.ToString(response.StatusCode));
            return;
        }

        //  Box's asynchronous commit response supplies Retry-After in seconds.
        retryHeader.SetString(response.GetHeaderField("Retry-After"));
        if (retryHeader.RegexMatch("^[0-9]{1,2}$",retryMatch,100) != 1) {
            Debug.WriteLine("Commit pending. Preserve the session and inspect Retry-After before resuming: " + retryHeader.GetAsString());
            return;
        }

        waitSeconds = Convert.ToInt32(retryHeader.GetAsString());
        if ((waitSeconds < 1) || (waitSeconds > 60)) {
            Debug.WriteLine("Commit pending. Resume commit after Retry-After: " + response.GetHeaderField("Retry-After"));
            return;
        }

        http.SleepMs(waitSeconds * 1000);
    }

    attempts = attempts + 1;
}

if (completed == false) {
    Debug.WriteLine("Commit still pending; retain session and part manifests to resume commit later.");
    return;
}

Debug.WriteLine("Upload committed: " + response.BodyStr);