Version 0.3 (11/02/11)
  - fixed some pointer comparisons in an attempt to prevent a crash where INKHandleStringRelease was called on a bad char*

Version 0.2 (10/31/11)
  - fixed lots of memory leaks

Version 0.1 (04/20/10)
  - initial version

Upload proxy specs for phase I:

1. Memory buffering (buffer the entire POST data in IOBuffer before connecting to OS) 
  1.1. Memory buffer size is configured with "mem_buffer_size" in config file. Default and minimum value is 32K
       You can increase it in the config file. If a request's size is larger than "mem_buffer_size" specifiied
       in config file, then the upload proxy feature will be disabled for this particular request

2. Disk buffering (buffer the entire POST data on disk before connecting to OS) 
  2.1. Use disk async IO. This involved some changes in ATS core
    . new APIs wrapping around ink_aio_read() and ink_aio_write()
    . change to distinguish between api call's AIO and cache's AIO 
    . guarantee api call's AIO only involves certain amount of threads
    . the number of threads is configurable in plugin's config file (default is 4)

  2.2. Directories and files generated on disk
    . base directory: FOOBAR/var/buffer_upload_tmp/ (configurable in config file)
    . number of subdirectories: 64 (configurable in config file)
    . filename are randomly generated
    . files will be removed when the entire data have been sent out to OS
    . remove dangling files (left on disk due to transaction interruption or traffic server crash) at startup time

  2.3. Default chunk size when reading from disk: 16K, configurable in config file

3. Default buffering mode: disk aio buffering mode
  3.1. to turn off disk buffering, add a "use_disk_buffer 0" line in config file

4. Trigger POST buffering on certain URLs
  4.1. certain URLs will be provided in a plain text file (one URL each line)
  4.2. specify filename in config file by "url_list_file"
  4.3. max length of each URL: 4096 (configurable in config file)
  4.4. use exact match, don't support regex for now 

5. URL conversion for Mail's specific URL format
  5.1. for now check if the "host" part in the URL is same as the proxy server name, then will do this conversion
  5.2. To turn on URL conversion feature, set "convert_url 1" in config file

6. All request headers inlcuding cookies plus the entire POST data will be buffered (either in memory or on disk)

7. Config file can be explicitly sepcified as a parameter in command line (in plugin.config file)


a sample config file:

use_disk_buffer         1
convert_url             1
chunk_size              1024
url_list_file           /tmp/url_list.conf
max_url_length          10000
base_dir                /tmp/test1
subdir_num              100
thread_num              10
mem_buffer_size         40000


default config file:    FOOBAR/etc/upload.conf

default config values:
use_disk_buffer         1
convert_url             0
chunk_size              16384
url_list_file           none
max_url_length          4096
base_dir                FOOBAR/var/buffer_upload_tmp
subdir_num              64
thread_num              4
mem_buffer_size         32768


