VB.NET Requires Chilkat v11.7.0+

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.

VB.NET

Dim success As Boolean = False

'  Requires Chilkat 11.7.0 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.
Dim curl As New Chilkat.HttpCurl
curl.SetVar("access_token","BOX_ACCESS_TOKEN")
curl.SetVar("parent_name","/")
'  Box's fixed root ID is an implementation detail; callers supply names.
curl.SetVar("parent_id","0")
Dim setupCommand As New Chilkat.StringBuilder
Dim setupReplacements As Integer

'  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) Then
    Debug.WriteLine(curl.LastErrorText)
    Exit Sub
End If


'  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) Then
    Debug.WriteLine(curl.LastErrorText)
    Exit Sub
End If


'  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) Then
    Debug.WriteLine(curl.LastErrorText)
    Exit Sub
End If


'  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) Then
    Debug.WriteLine(curl.LastErrorText)
    Exit Sub
End If


'  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) Then
    Debug.WriteLine(curl.LastErrorText)
    Exit Sub
End If


'  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) Then
    Debug.WriteLine(curl.LastErrorText)
    Exit Sub
End If


'  Register output rules once. Chilkat 11.7.0 evaluates {{name}} variables
'  when extracting each output, using the current value at that time.
success = curl.AddOutput2("findParent","entries","name","{{parent_name}}",True,"id","parent_id")
If (success <> True) Then
    Debug.WriteLine(curl.LastErrorText)
    Exit Sub
End If

success = curl.AddOutput2("findFolder","entries","name","{{folder_name}}",True,"id","folder_id")
If (success <> True) Then
    Debug.WriteLine(curl.LastErrorText)
    Exit Sub
End If

success = curl.AddOutput2("findFile","entries","name","{{file_name}}",True,"id","file_id")
If (success <> True) Then
    Debug.WriteLine(curl.LastErrorText)
    Exit Sub
End If

success = curl.AddOutput2("findDestination","entries","name","{{destination_name}}",True,"id","destination_id")
If (success <> True) Then
    Debug.WriteLine(curl.LastErrorText)
    Exit Sub
End If

success = curl.AddOutput("getFileDetails","file_version.id","file_version_id")
If (success <> True) Then
    Debug.WriteLine(curl.LastErrorText)
    Exit Sub
End If

success = curl.AddOutput("getFileDetails","sha1","file_sha1")
If (success <> True) Then
    Debug.WriteLine(curl.LastErrorText)
    Exit Sub
End If

success = curl.AddOutput("getEnterprise","enterprise.id","enterprise_id")
If (success <> True) Then
    Debug.WriteLine(curl.LastErrorText)
    Exit Sub
End If

'  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.
Dim parentName As String = "/"
Dim folderName As String = "documents"
If ((curl.GetVar("parent_name") <> parentName) Or ((parentName = "/") And (curl.VarDefined("parent_id") = False))) Then
    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 = "/") Then
        curl.SetVar("parent_id","0")
    End If

End If

If (curl.GetVar("folder_name") <> folderName) Then
    curl.SetVar("folder_name",folderName)
    curl.ClearVar("folder_id")
    curl.ClearVar("file_id")
    curl.ClearVar("file_version_id")
    curl.ClearVar("file_sha1")
End If

'  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("*")
Dim authorizedCommand1 As New Chilkat.StringBuilder
authorizedCommand1.SetString("curl -X GET ""https://api.box.com/2.0/folders/{{folder_id}}?fields=id"" -H ""Authorization: Bearer {{access_token}}""")
Dim headerReplacement1 As Integer = authorizedCommand1.Replace("{{access_token}}",curl.GetVar("access_token"))
success = curl.DoYourThing(authorizedCommand1.GetAsString())
If ((success <> True) Or (curl.StatusCode <> 200)) Then
    Debug.WriteLine("Box request failed. HTTP status: " & curl.StatusCode)
    Debug.WriteLine("Failure reason: " & curl.FailReason)
    Debug.WriteLine(curl.ResponseBodyStr)
    Exit Sub
End If

'  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.
Dim localPath As String = "qa_data/large-document.zip"
Dim file As New Chilkat.FileAccess
'  Check the decimal size before converting so an oversized file cannot overflow int.
Dim sizeString As String = file.FileSizeStr(localPath)
If (file.LastMethodSuccess <> True) Then
    Debug.WriteLine(file.LastErrorText)
    Exit Sub
End If

Dim sizeText As New Chilkat.StringBuilder
sizeText.SetString(sizeString)
Dim sizeMatch As New Chilkat.JsonObject
If (sizeText.RegexMatch("^([0-9]{1,9}|1[0-9]{9}|2000000000)$",sizeMatch,100) <> 1) Then
    Debug.WriteLine("Choose an input between 20 MB and 2 GB for this example.")
    Exit Sub
End If

Dim fileSize As Integer = Convert.toInt32(sizeString)
If (fileSize < 20971520) Then
    Debug.WriteLine("Choose an input between 20 MB and 2 GB for this example.")
    Exit Sub
End If

Dim http As New Chilkat.Http
http.AuthToken = curl.GetVar("access_token")
Dim response As New Chilkat.HttpResponse
Dim request As 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) Then
    Debug.WriteLine(http.LastErrorText)
    Exit Sub
End If

If (response.StatusCode <> 201) Then
    Debug.WriteLine(response.BodyStr)
    Exit Sub
End If

Dim session As New Chilkat.JsonObject
success = session.Load(response.BodyStr)
If (success <> True) Then
    Debug.WriteLine(session.LastErrorText)
    Exit Sub
End If

success = session.WriteFile("qa_output/box_upload_session.json")
If (success <> True) Then
    Debug.WriteLine(session.LastErrorText)
    Exit Sub
End If

Dim partSize As Integer = session.IntOf("part_size")
Dim uploadUrl As String = session.StringOf("session_endpoints.upload_part")
Dim commitUrl As String = session.StringOf("session_endpoints.commit")
If ((partSize <= 0) Or (uploadUrl = "") Or (commitUrl = "")) Then
    Debug.WriteLine("Invalid session response.")
    Exit Sub
End If

Dim hash As New Chilkat.Crypt2
hash.HashAlgorithm = "sha1"
hash.EncodingMode = "base64"
Dim fileDigest As String = hash.HashFileENC(localPath)
If (hash.LastMethodSuccess <> True) Then
    Debug.WriteLine(hash.LastErrorText)
    Exit Sub
End If

success = file.FileOpen(localPath,2147483648,1,3,0)
If (success <> True) Then
    Debug.WriteLine(file.LastErrorText)
    Exit Sub
End If

Dim commit As New Chilkat.JsonObject
Dim partResponse As New Chilkat.JsonObject
Dim chunk As New Chilkat.BinData
Dim range As New Chilkat.StringBuilder
Dim digestHeader As New Chilkat.StringBuilder
Dim offset As Integer = 0
Dim partIndex As Integer = 0
Dim partLength As Integer
Dim lastByte As Integer
Dim partDigest As String
While offset < fileSize
    chunk.Clear()
    success = file.FileReadBd(partSize,chunk)
    If (success <> True) Then
        Debug.WriteLine(file.LastErrorText)
        file.FileClose()
        Exit Sub
    End If

    partLength = chunk.NumBytes
    If (partLength <= 0) Then
        Debug.WriteLine("Unexpected end of file.")
        file.FileClose()
        Exit Sub
    End If

    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) Then
        Debug.WriteLine(hash.LastErrorText)
        file.FileClose()
        Exit Sub
    End If

    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) Or (response.StatusCode <> 200)) Then
        Debug.WriteLine("Part failed. HTTP status: " & response.StatusCode)
        Debug.WriteLine(response.BodyStr)
        Debug.WriteLine("Inspect the saved session and server list_parts before retrying this part.")
        file.FileClose()
        Exit Sub
    End If

    success = partResponse.Load(response.BodyStr)
    If (success <> True) Then
        file.FileClose()
        Exit Sub
    End If

    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) Then
        Debug.WriteLine(commit.LastErrorText)
        file.FileClose()
        Exit Sub
    End If

    offset = offset + partLength
    partIndex = partIndex + 1
End While
file.FileClose()
http.RemoveRequestHeader("Content-Range")
digestHeader.SetString("sha=")
digestHeader.Append(fileDigest)
http.SetRequestHeader("Digest",digestHeader.GetAsString())
Dim attempts As Integer = 0
Dim waitSeconds As Integer
Dim retryHeader As New Chilkat.StringBuilder
Dim retryMatch As New Chilkat.JsonObject
Dim completed As Boolean = False
While (attempts < 10) And (completed = False)
    success = http.HttpJson("POST",commitUrl,commit,"application/json",response)
    If (success <> True) Then
        Debug.WriteLine("Commit failed: " & response.StatusCode)
        Debug.WriteLine(response.BodyStr)
        Exit Sub
    End If

    If (response.StatusCode = 201) Then
        completed = True
    Else
        If (response.StatusCode <> 202) Then
            Debug.WriteLine("Unexpected commit status: " & response.StatusCode)
            Exit Sub
        End If

        '  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) Then
            Debug.WriteLine("Commit pending. Preserve the session and inspect Retry-After before resuming: " & retryHeader.GetAsString())
            Exit Sub
        End If

        waitSeconds = Convert.toInt32(retryHeader.GetAsString())
        If ((waitSeconds < 1) Or (waitSeconds > 60)) Then
            Debug.WriteLine("Commit pending. Resume commit after Retry-After: " & response.GetHeaderField("Retry-After"))
            Exit Sub
        End If

        http.SleepMs(waitSeconds * 1000)
    End If

    attempts = attempts + 1
End While
If (completed = False) Then
    Debug.WriteLine("Commit still pending; retain session and part manifests to resume commit later.")
    Exit Sub
End If

Debug.WriteLine("Upload committed: " & response.BodyStr)