Imported Upstream version 2.0.3

1 files changed, 111 insertions, 0 deletions

diff --git a/tool/space_used.tcl b/tool/space_used.tcl
new file mode 100644
index 0000000..2044aa3
--- /dev/null
+++ b/tool/space_used.tcl
@@ -0,0 +1,111 @@
+# 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;"