Summary:
Current Message
```
sst_dump [--command=check|scan|none|raw] [--verify_checksum] --file=data_dir_OR_sst_file [--output_hex] [--input_key_hex] [--from=<user_key>] [--to=<user_key>] [--read_num=NUM] [--show_properties] [--show_compression_sizes] [--show_compression_sizes [--set_block_size=<block_size>]]
```
New message
```
sst_dump --file=<data_dir_OR_sst_file> [--command=check|scan|raw]
--file=<data_dir_OR_sst_file>
Path to SST file or directory containing SST files
--command=check|scan|raw
check: Iterate over entries in files but dont print anything except if an error is encounterd (default command)
scan: Iterate over entries in files and print them to screen
raw: Dump all the table contents to <file_name>_dump.txt
--output_hex
Can be combined with scan command to print the keys and values in Hex
--from=<user_key>
Key to start reading from when executing check|scan
--to=<user_key>
Key to stop reading at when executing check|scan
--read_num=<num>
Maximum number of entries to read when executing check|scan
--verify_checksum
Verify file checksum when executing check|scan
--input_key_hex
Can be combined with --from and --to to indicate that these values are encoded in Hex
--show_properties
Print table properties after iterating over the file
--show_compression_sizes
Independent command that will recreate the SST file using 16K block size with different
compressions and report the size of the file using such compression
--set_block_size=<block_size>
Can be combined with --show_compression_sizes to set the block size that will be used
when trying different compression algorithms
```
Test Plan: none
Reviewers: yhchiang, andrewkr, kradhakrishnan, yiwu, sdong
Reviewed By: sdong
Subscribers: andrewkr, dhruba
Differential Revision: https://reviews.facebook.net/D56325
0522990358