Class: MiqBerkeleyDB::MiqBdb

Inherits:
Object
  • Object
show all
Defined in:
lib/db/MiqBdb/MiqBdb.rb

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(fileName = nil, fs = nil) ⇒ MiqBdb

Returns a new instance of MiqBdb.



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# File 'lib/db/MiqBdb/MiqBdb.rb', line 133

def initialize(fileName = nil, fs = nil)
  @fs = fs unless fs.nil?
  open(fileName) unless fileName.nil?
end

Instance Attribute Details

#db ⇒ Object (readonly)

Returns the value of attribute db.



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# File 'lib/db/MiqBdb/MiqBdb.rb', line 131

def db
  @db
end

#header ⇒ Object (readonly)

Returns the value of attribute header.



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# File 'lib/db/MiqBdb/MiqBdb.rb', line 131

def header
  @header
end

Instance Method Details

#close ⇒ Object

Close the database



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# File 'lib/db/MiqBdb/MiqBdb.rb', line 173

def close
  @db.close
  @file.close
  @db = @header = @file = @filename = nil
end

#dump ⇒ Object 



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# File 'lib/db/MiqBdb/MiqBdb.rb', line 224

def dump
  out = "File Header\n"
  out << "  lsn:             #{@header['lsn']}\n"
  out << "  pgno:            #{@header['pgno']}\n"
  out << "  magic:           0x#{'%08x' % @header['magic']}\n"
  out << "  version:         #{@header['version']}\n"
  out << "  pagesize:        #{@header['pagesize']}\n"
  out << "  encrypt_alg:     #{@header['encrypt_alg']}\n"
  out << "  page type:       #{MiqBdbPage.type2string(@header['p_type'])}\n"
  out << "  metaflags:       0x#{'%08x' % @header['metaflags']}\n"
  out << "  free:            #{@header['free']}\n"
  out << "  last_pgno:       #{@header['last_pgno']}\n"
  out << "  key_count:       #{@header['key_count']}\n"
  out << "  record_count:    #{@header['record_count']}\n"
  out << "  flags:           0x#{'%08x' % @header['flags']}\n"
  out << "  uid:             #{uid_format}\n"
  out << "\n"
  out
end

#each ⇒ Object 



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# File 'lib/db/MiqBdb/MiqBdb.rb', line 262

def each
  @db.pages do |page|
    page.pairs do |k, v|
      yield k, v
    end
  end
end

#each_key ⇒ Object 



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# File 'lib/db/MiqBdb/MiqBdb.rb', line 270

def each_key
  @db.pages do |page|
    page.keys do |k|
      yield k
    end
  end
end

#each_value ⇒ Object 



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# File 'lib/db/MiqBdb/MiqBdb.rb', line 278

def each_value
  @db.pages do |page|
    page.values do |v|
      yield v
    end
  end
end

#keys ⇒ Object 



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# File 'lib/db/MiqBdb/MiqBdb.rb', line 244

def keys
  keys = []
  each_key { |k| keys << k }
  keys
end

#nbuckets ⇒ Object 



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# File 'lib/db/MiqBdb/MiqBdb.rb', line 184

def nbuckets
  @db.header.max_bucket + 1
end

#nkeys ⇒ Object 



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# File 'lib/db/MiqBdb/MiqBdb.rb', line 188

def nkeys
  @header["key_count"]
end

#npages ⇒ Object 



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# File 'lib/db/MiqBdb/MiqBdb.rb', line 196

def npages
  @header["last_pgno"] + 1
end

#nrecs ⇒ Object 



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# File 'lib/db/MiqBdb/MiqBdb.rb', line 192

def nrecs
  @header["record_count"]
end

#open(filename) ⇒ Object

Open the database



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# File 'lib/db/MiqBdb/MiqBdb.rb', line 139

def open(filename)
  # Get header & check.
  @filename = filename
  @file = fileOpen(@filename)
  @header = DBHEADER.decode(@file.read(SIZEOF_DBHEADER))

  # Holds the page buf if we read all pages
  @read_buf = nil

  # Check header version - simple warning if less than 8.
  if @header["version"] < 8
    msg = "MiqBerkeleyDB: Database header version is less than 8."
    if $log
      $log.warn(msg)
    else
      puts "WARNING: " + msg
    end
  end

  # We don't support encryption.
  raise "MiqBerkeleyDB: This database uses encryption." if @header["encrypt_alg"] != 0

  # Open db type (only hash for now, may expand to plugins in the future).
  @db = case @header["magic"]
        when DB_HASHMAGIC then   MiqBdbHashDatabase.new(self)
        when DB_BTREEMAGIC then  MiqBdbBtreeDatabase.new(self)
        when DB_QAMMAGIC then    raise "MiqBerkeleyDB: Database type is Queue"
        when DB_LOGMAGIC then    raise "MiqBerkeleyDB: Database type is Log"
        when DB_RENAMEMAGIC then raise "MiqBerkeleyDB: Database type is Rename"
        else                     raise "MiqBerkeleyDB: Database type #{@header['magic']} is not supported"
        end
end

#pages ⇒ Object 



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# File 'lib/db/MiqBdb/MiqBdb.rb', line 204

def pages
  @db.pages { |page| yield page }
end

#pagesize ⇒ Object 



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# File 'lib/db/MiqBdb/MiqBdb.rb', line 200

def pagesize
  @header["pagesize"]
end

#read(len) ⇒ Object 



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# File 'lib/db/MiqBdb/MiqBdb.rb', line 179

def read(len)
  raise "File not open" if @file.nil?
  @file.read(len)
end

#readAllPages ⇒ Object 



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# File 'lib/db/MiqBdb/MiqBdb.rb', line 219

def readAllPages
  @file.seek(0)
  @read_buf = @file.read(pagesize * npages)
end

#readPage(pagenum, buf = @read_buf) ⇒ Object 



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# File 'lib/db/MiqBdb/MiqBdb.rb', line 208

def readPage(pagenum, buf = @read_buf)
  where = (pagenum * pagesize)
  page = if buf.nil?
           @file.seek(where)
           @file.read(pagesize)
         else
           buf[where, pagesize]
         end
  page
end

#size ⇒ Object 



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# File 'lib/db/MiqBdb/MiqBdb.rb', line 256

def size
  size = 0
  each_key { |_k| size += 1 }
  size
end

#values ⇒ Object 



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# File 'lib/db/MiqBdb/MiqBdb.rb', line 250

def values
  values = []
  each_value { |v| values << v }
  values
end