[sqlite] use mmap

Summary:
SQLite can use memory-mapped databases, which can improve read performance (only read due to the way it's used in SQLite).

This is exposed via a command line parameter that defaults to enabled for Linux/Darwin and disabled for Windows (untested).

Reviewed By: jvillard

Differential Revision:
D50228601

Privacy Context Container: L1122176

fbshipit-source-id: 8e42d3bb66a07851b6bfc210eec5170983508886

infer/man/man1/infer-analyze.txt

@@ -409,6 +409,10 @@ OPTIONS
        --sqlite-max-blob-size int
            Maximum blob/string size for data written in SQLite.
 
+       --sqlite-mmap-size int
+           Size of memory map for mmaped SQLite databases, zero value
+           disables memory mapping.
+
        --sqlite-page-size int
            SQLite page size in bytes, must be a power of two between 512 and
            65536.

infer/man/man1/infer-capture.txt

@@ -139,6 +139,10 @@ OPTIONS
        --sqlite-max-blob-size int
            Maximum blob/string size for data written in SQLite.
 
+       --sqlite-mmap-size int
+           Size of memory map for mmaped SQLite databases, zero value
+           disables memory mapping.
+
        --sqlite-page-size int
            SQLite page size in bytes, must be a power of two between 512 and
            65536.

infer/man/man1/infer-full.txt

@@ -1845,6 +1845,10 @@ OPTIONS
            Maximum blob/string size for data written in SQLite.       
     See also infer-analyze(1), infer-capture(1), and infer-run(1).
 
+       --sqlite-mmap-size int
+           Size of memory map for mmaped SQLite databases, zero value
+           disables memory mapping.           See also infer-analyze(1), infer-capture(1), and infer-run(1).
+
        --sqlite-page-size int
            SQLite page size in bytes, must be a power of two between 512 and
            65536.           See also infer-analyze(1), infer-capture(1), and infer-run(1).

infer/man/man1/infer-run.txt

@@ -157,6 +157,10 @@ OPTIONS
        --sqlite-max-blob-size int
            Maximum blob/string size for data written in SQLite.
 
+       --sqlite-mmap-size int
+           Size of memory map for mmaped SQLite databases, zero value
+           disables memory mapping.
+
        --sqlite-page-size int
            SQLite page size in bytes, must be a power of two between 512 and
            65536.

infer/man/man1/infer.txt

@@ -1845,6 +1845,10 @@ OPTIONS
            Maximum blob/string size for data written in SQLite.       
     See also infer-analyze(1), infer-capture(1), and infer-run(1).
 
+       --sqlite-mmap-size int
+           Size of memory map for mmaped SQLite databases, zero value
+           disables memory mapping.           See also infer-analyze(1), infer-capture(1), and infer-run(1).
+
        --sqlite-page-size int
            SQLite page size in bytes, must be a power of two between 512 and
            65536.           See also infer-analyze(1), infer-capture(1), and infer-run(1).

infer/src/base/Config.ml

@@ -3280,6 +3280,20 @@ and sqlite_max_blob_size =
     "Maximum blob/string size for data written in SQLite."
 
 
+and sqlite_mmap_size =
+  let default =
+    match Version.build_platform with
+    | Windows ->
+        0 (* disable as untested *)
+    | Linux | Darwin ->
+        256 * 1024 * 1024 (* 256 Mb, see https://www.sqlite.org/mmap.html *)
+  in
+  CLOpt.mk_int ~long:"sqlite-mmap-size" ~default
+    ~in_help:
+      InferCommand.[(Analyze, manual_generic); (Capture, manual_generic); (Run, manual_generic)]
+    "Size of memory map for mmaped SQLite databases, zero value disables memory mapping."
+
+
 and sqlite_vfs = CLOpt.mk_string_opt ~long:"sqlite-vfs" "VFS for SQLite"
 
 and subtype_multirange =
@@ -4518,6 +4532,8 @@ and sqlite_lock_timeout = !sqlite_lock_timeout
 
 and sqlite_max_blob_size = !sqlite_max_blob_size
 
+and sqlite_mmap_size = !sqlite_mmap_size
+
 and sqlite_vfs = !sqlite_vfs
 
 and starvation_skip_analysis = !starvation_skip_analysis

infer/src/base/Config.mli

@@ -819,6 +819,8 @@ val sqlite_lock_timeout : int
 
 val sqlite_max_blob_size : int
 
+val sqlite_mmap_size : int
+
 val sqlite_vfs : string option
 
 val starvation_skip_analysis : Yojson.Basic.t

infer/src/base/Database.ml

@@ -301,6 +301,8 @@ end = struct
         db_path
     in
     Sqlite3.busy_timeout db Config.sqlite_lock_timeout ;
+    SqliteUtils.exec db ~log:"mmap"
+      ~stmt:(Printf.sprintf "PRAGMA mmap_size=%d" Config.sqlite_mmap_size) ;
     SqliteUtils.exec db ~log:"synchronous=OFF" ~stmt:"PRAGMA synchronous=OFF" ;
     SqliteUtils.exec db ~log:"sqlite cache size"
       ~stmt:(Printf.sprintf "PRAGMA cache_size=%i" Config.sqlite_cache_size) ;