Import SQLite 3.10.2.

third_party/sqlite/src/tool/space_used.tcl

-# Run this TCL script using "testfixture" in order get a report that shows
-# how much disk space is used by a particular data to actually store data
-# versus how much space is unused.
-#
-
-# Get the name of the database to analyze
-#
-if {[llength $argv]!=1} {
-  puts stderr "Usage: $argv0 database-name"
-  exit 1
-}
-set file_to_analyze [lindex $argv 0]
-
-# Open the database
-#
-sqlite db [lindex $argv 0]
-set DB [btree_open [lindex $argv 0]]
-
-# Output the schema for the generated report
-#
-puts \
-{BEGIN;
-CREATE TABLE space_used(
-   name clob,        -- Name of a table or index in the database file
-   is_index boolean, -- TRUE if it is an index, false for a table
-   payload int,      -- Total amount of data stored in this table or index
-   pri_pages int,    -- Number of primary pages used
-   ovfl_pages int,   -- Number of overflow pages used
-   pri_unused int,   -- Number of unused bytes on primary pages
-   ovfl_unused int   -- Number of unused bytes on overflow pages
-);}
-
-# This query will be used to find the root page number for every index and
-# table in the database.
-#
-set sql {
-  SELECT name, type, rootpage FROM sqlite_master
-  UNION ALL
-  SELECT 'sqlite_master', 'table', 2
-  ORDER BY 1
-}
-
-# Initialize variables used for summary statistics.
-#
-set total_size 0
-set total_primary 0
-set total_overflow 0
-set total_unused_primary 0
-set total_unused_ovfl 0
-
-# Analyze every table in the database, one at a time.
-#
-foreach {name type rootpage} [db eval $sql] {
-  set cursor [btree_cursor $DB $rootpage 0]
-  set go [btree_first $cursor]
-  set size 0
-  catch {unset pg_used}
-  set unused_ovfl 0
-  set n_overflow 0
-  while {$go==0} {
-    set payload [btree_payload_size $cursor]
-    incr size $payload
-    set stat [btree_cursor_dump $cursor]
-    set pgno [lindex $stat 0]
-    set freebytes [lindex $stat 4]
-    set pg_used($pgno) $freebytes
-    if {$payload>238} {
-      set n [expr {($payload-238+1019)/1020}]
-      incr n_overflow $n
-      incr unused_ovfl [expr {$n*1020+238-$payload}]
-    }
-    set go [btree_next $cursor]
-  }
-  btree_close_cursor $cursor
-  set n_primary [llength [array names pg_used]]
-  set unused_primary 0
-  foreach x [array names pg_used] {incr unused_primary $pg_used($x)}
-  regsub -all ' $name '' name
-  puts -nonewline "INSERT INTO space_used VALUES('$name'"
-  puts -nonewline ",[expr {$type=="index"}]"
-  puts ",$size,$n_primary,$n_overflow,$unused_primary,$unused_ovfl);"
-  incr total_size $size
-  incr total_primary $n_primary
-  incr total_overflow $n_overflow
-  incr total_unused_primary $unused_primary
-  incr total_unused_ovfl $unused_ovfl
-}
-
-# Output summary statistics:
-#
-puts "-- Total payload size: $total_size"
-puts "-- Total pages used: $total_primary primary and $total_overflow overflow"
-set file_pgcnt [expr {[file size [lindex $argv 0]]/1024}]
-puts -nonewline "-- Total unused bytes on primary pages: $total_unused_primary"
-if {$total_primary>0} {
-  set upp [expr {$total_unused_primary/$total_primary}]
-  puts " (avg $upp bytes/page)"
-} else {
-  puts ""
-}
-puts -nonewline "-- Total unused bytes on overflow pages: $total_unused_ovfl"
-if {$total_overflow>0} {
-  set upp [expr {$total_unused_ovfl/$total_overflow}]
-  puts " (avg $upp bytes/page)"
-} else {
-  puts ""
-}
-set n_free [expr {$file_pgcnt-$total_primary-$total_overflow}]
-if {$n_free>0} {incr n_free -1}
-puts "-- Total pages on freelist: $n_free"
-puts "COMMIT;"