Group 2 Web Service

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Group 2 Web Service For Collaborative editing

• Uses scalable Client-Server architecture to
  minimize network
• communication and improve reliability
• Provides Upload, Download, Find functionality
• Easily extendable to near real-time live
  collaboration

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ARCHITECTURE
download
upload
Web Service
Editor
Editor
download
upload
Line 1 Line 2 Line 3
Line 1 Line 2 Line 3
Document Repository
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UPLOAD
There are 2 options when uploading a file to the
web-server
Option 1) Upload the entire file at once
Option 2) Upload the file line by line
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Option 1 Upload the entire file
Uploads the desired file. Entire file is
received. If a file with the same name exists on
the server, the contents of the file on the
server are over written.
Function int ns__uploadFile(char fileName, int
bytes, char fileContents, char status)
Input fileName name of the file to upload to
the web-service bytes size of the file in
bytes fileContents actual contents of the file
to be uploaded (string)
Output - the function can return the following
strings 1) "CNO!" Could Not Open the requested
file name 2) "CNW!" Could Not Write to
requested file 3) "OK!" contents of the file
uploaded and written correctly.
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Option 2 Upload the file line by line
Before the client can begin uploading the file
the user must call the following function in
order to create the physical file on the server.
Creates a file on the server to be uploaded line
by line thus enabling the user to manually
manage network flow of traffic. If a file with
the same name exists on the server, the contents
of the file on the server are over written.
Function int ns__startUpload(char fileName,
char status)
Input fileName name of the file to upload to
the web-service
Output - the function can return the following
strings 1) "CNC!" Could Not Create the
requested file on the server 2) "OK!" contents
of the file uploaded and written correctly. .
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Option 2 Upload the file line by line
Once the file has been created the user can begin
the line by line upload.
Uploads a file line by line thus enabling the
user to manually manage network flow of traffic.
Caller sets the length of line on the client
side. Each line is appended to the file created
by the startUpload() function.
Function int ns__upload(char fileName, char
text, char result)
Input fileName name of the file to upload to
the webservice text the contents of each line
Output - the function can return the following
strings 1) "CNO! Could Not Open the requested
file name 2) "CNA!" Could Not Append to
requested file 3) "OK!" contents of the file
uploaded and written correctly. .
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DOWNLOAD
There are 2 options when uploading a file to the
web-server
Option 1) Download the entire file at once
Option 2) Download the file line by line
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Option 1 Download the entire file
Downloads the requested file. Entire file is
sent.
Function int ns__downloadFile(char fileName,
char fileContents)
Input fileName name of the file to download
from the web-service
Output - the function can return the following
strings 1) "DNE!" the requested file Does Not
Exist on the server 2) all contents of the file
(as a string)
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Option 2 Download the file line by line
Downloads the requested file line by line. The
caller sets the length of each line in bytes to
be downloaded. This enables the user to manually
manage network flow of traffic.
Function int ns__download(char fileName, long
position, int bytes, char result)
Input filename Name of the file to download
from the web-service position Position of the
next line in the file to download bytes Size
of each line to download
Output - the function can return the following
strings 1) "DNE!" the requested file Does Not
Exist on the server 2) "EOF!" the file has
reached the end. 3) actual line of text from the
requested file .
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FIND
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FIND sending to web-service
Send the search string to the server as well as
the location of the search string in the file.
Also sessionID is required to keep track of all
the users working on the same file..
Function int ns__setFind(char sessionID,int
offset, char searchString, char result)
Input sessionID users/cliens
sessionID offset location of the seach string
in the file (byte offset) searchString string
the user has searched for
Output - the function can return the following
strings 1) "OK!" uploaded all information
correctly 2) "NOT OK! the information was not
uploaded
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FIND receive from the web-service
Sends the client the offset of the last searched
string according to the sessionID.
Function int ns__getFindOffset(char
sessionID,char result)
Input sessionID users/clients sessionID

• Output - the function can return the following
  strings
• the offset/byte location of the last search for
  the given session.
• 2) "DNE!" the information for the given session
  ID Does Not Exist.
• In other words there were no searches
  performed yet.

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FIND receive from the web-service
Sends the client the search string of the last
search according to the sessionID.
Function int ns__getFindString(char
sessionID,char result)
Input sessionID users/clients sessionID

• Output - the function can return the following
  strings
• the search string of the last search for the
  given session.
• 2) "DNE!" the information for the given session
  ID Does Not Exist.
• In other words there were no searches
  performed yet.

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Ideas for extension of web service

• To inform web service of local changes
• modify upload operation to allow byte offfset of
  text
• accumulate changes locally
• send periodic uploads with incremental changes
  and byte offsets

• To receive changes from web service
• modify download operation to allow byte offfset
  of text
• accumulate changes on web service using log
• periodically download changes from web service
• so that client buffer remains up to date