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#!/usr/bin/env python
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# Loads a command's CSV output stream into a PostgreSQL table.
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# When no command is specified, just cleans up the specified table.
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# The command may be run more than once.
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import csv
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import os.path
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import re
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import subprocess
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import sys
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sys.path.append(os.path.dirname(__file__)+"/../lib")
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import csvs
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import exc
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import opts
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import sql
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import sql_io
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import sql_gen
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import streams
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import strings
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import util
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def main():
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    # Usage
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    env_names = []
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    def usage_err():
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        raise SystemExit('Usage: '+opts.env_usage(env_names)+' '+sys.argv[0]
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            +' [input_cmd args...]')
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    # Parse args
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    input_cmd = sys.argv[1:]
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    # Get config from env vars
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    table = opts.get_env_var('table', None, env_names)
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    schema = opts.get_env_var('schema', 'public', env_names)
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    has_row_num = opts.env_flag('has_row_num', True, env_names)
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    db_config = opts.get_env_vars(sql.db_config_names, None, env_names)
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    verbosity = util.cast(float, opts.get_env_var('verbosity', 3, env_names))
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    if not (table != None and 'engine' in db_config): usage_err()
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    # Connect to DB
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    def log(msg, level=1):
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        '''Higher level -> more verbose'''
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        if level <= verbosity:
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            sys.stderr.write(strings.to_raw_str(msg.rstrip('\n')+'\n'))
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    db = sql.connect(db_config, log_debug=log)
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    table = sql_gen.Table(table, schema)
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    use_copy_from = [True]
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    # Loads data into the table using the currently-selected approach.
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    def load():
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        # Open input stream
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        proc = subprocess.Popen(input_cmd, stdout=subprocess.PIPE, bufsize=-1)
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        in_ = proc.stdout
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        # Get format info
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        info = csvs.stream_info(in_, parse_header=True)
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        dialect = info.dialect
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        if csvs.is_tsv(dialect): use_copy_from[0] = False
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        col_names = map(strings.to_unicode, info.header)
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        for i, col in enumerate(col_names): # replace empty column names
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            if col == '': col_names[i] = 'column_'+str(i)
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        # Select schema and escape names
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        def esc_name(name): return db.esc_name(name)
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        typed_cols = [sql_gen.TypedCol(v, 'text') for v in col_names]
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        log('Creating table')
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        sql.create_table(db, table, typed_cols, has_pkey=False,
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            col_indexes=False)
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        # Remove rows from any failed COPY FROM
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        sql.truncate(db, table)
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        def load_():
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            # Create COPY FROM statement
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            if use_copy_from[0]:
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                copy_from = ('COPY '+table.to_str(db)+' FROM STDIN DELIMITER '
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                    +db.esc_value(dialect.delimiter)+' NULL '+db.esc_value(''))
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                assert not csvs.is_tsv(dialect)
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                copy_from += ' CSV'
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                if dialect.quoting != csv.QUOTE_NONE:
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                    quote_str = db.esc_value(dialect.quotechar)
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                    copy_from += ' QUOTE '+quote_str
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                    if dialect.doublequote: copy_from += ' ESCAPE '+quote_str
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                copy_from += ';\n'
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            # Load the data
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            line_in = streams.ProgressInputStream(in_, sys.stderr, n=1000)
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            try:
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                if use_copy_from[0]:
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                    log('Using COPY FROM')
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                    log(copy_from, level=2)
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                    db.db.cursor().copy_expert(copy_from, line_in)
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                else:
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                    log('Using INSERT')
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                    cols_ct = len(col_names)
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                    for row in csvs.make_reader(line_in, dialect):
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                        row = map(strings.to_unicode, row)
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                        util.list_set_length(row, cols_ct) # truncate extra cols
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                        sql.insert(db, table, row, cacheable=False, log_level=5)
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            finally:
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                line_in.close() # also closes proc.stdout
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                proc.wait()
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            if has_row_num: sql.add_row_num(db, table)
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        sql.with_savepoint(db, load_)
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    if input_cmd != []:
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        try: load()
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        except sql.DatabaseErrors, e:
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            if use_copy_from[0]: # first try
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                exc.print_ex(e, plain=True)
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                use_copy_from[0] = False
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                load() # try again with different approach
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            else: raise
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    log('Cleaning up table')
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    sql_io.cleanup_table(db, table)
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    log('Vacuuming and reanalyzing table')
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    sql.vacuum(db, table)
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main()