Skip to content

Support for fixed-size arrays #2

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Open
stathissideris wants to merge 3 commits into
base: master
Choose a base branch
from
Open

Support for fixed-size arrays #2

Changes from all commits
Commits
Show all changes
3 commits
Select commit Hold shift + click to select a range
8f8ef33
Added support for fixed-size arrays with [:byte 4]
stathissideris Aug 22, 2011
5927d24
Added support for reading fixed-length strings with [:fstring 4]
stathissideris Aug 22, 2011
d5732b0
Added support for reading little endian int16s and int32s and a funct…
stathissideris Aug 23, 2011
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
96 changes: 67 additions & 29 deletions src/byte_spec.clj
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -25,42 +25,70 @@
(.writeByte *spec-out* (count s))
(.write *spec-out* (.getBytes s)))

(defn read-fstring [len]
(let [bytes (byte-array len)]
(.readFully *spec-in* bytes)
(String. bytes)))

(defn- write-fstring [s len]
(let [actual (if (<= (count s) len)
(.substring s 0 len)
(apply str s (take (- len (count s)) (repeat " "))))]
(.write *spec-out* (.getBytes actual))))

(defn- read-int16-little []
(let [b1 (.readUnsignedByte *spec-in*)
b2 (bit-shift-left (.readUnsignedByte *spec-in*) 8)]
(reduce bit-or [b1 b2])))

(defn- read-int32-little []
(let [b1 (.readUnsignedByte *spec-in*)
b2 (bit-shift-left (.readUnsignedByte *spec-in*) 8)
b3 (bit-shift-left (.readUnsignedByte *spec-in*) 16)
b4 (bit-shift-left (.readUnsignedByte *spec-in*) 24)]
(reduce bit-or [b1 b2 b3 b4])))

(defn seek-by [offset]
(.seek *spec-in* (+ (.getFilePointer *spec-in*) offset)))

;; Standard numeric types + Pascal style strings.
;; pstring => a byte giving the string length followed by the ascii bytes
(def READERS {
:int8 #(.readByte *spec-in*)
:int16 #(.readShort *spec-in*)
:int32 #(.readInt *spec-in*)
:int64 #(.readLong *spec-in*)
:float32 #(.readFloat *spec-in*)
:int8 #(.readByte *spec-in*)
:int16 #(.readShort *spec-in*)
:int16-l read-int16-little
:int32 #(.readInt *spec-in*)
:int32-l read-int32-little
:int64 #(.readLong *spec-in*)
:float32 #(.readFloat *spec-in*)
:float64 #(.readDouble *spec-in*)

:byte #(.readByte *spec-in*)
:short #(.readShort *spec-in*)
:int #(.readInt *spec-in*)
:long #(.readLong *spec-in*)
:float #(.readFloat *spec-in*)
:byte #(.readByte *spec-in*)
:short #(.readShort *spec-in*)
:int #(.readInt *spec-in*)
:long #(.readLong *spec-in*)
:float #(.readFloat *spec-in*)
:double #(.readDouble *spec-in*)

:string read-pstring
:string read-pstring
})

(def WRITERS {
:int8 #(.writeByte *spec-out* %1)
:int16 #(.writeShort *spec-out* %1)
:int32 #(.writeInt *spec-out* %1)
:int64 #(.writeLong *spec-out* %1)
:int8 #(.writeByte *spec-out* %1)
:int16 #(.writeShort *spec-out* %1)
:int32 #(.writeInt *spec-out* %1)
:int64 #(.writeLong *spec-out* %1)
:float32 #(.writeFloat *spec-out* %1)
:float64 #(.writeDouble *spec-out* %1)

:byte #(.writeByte *spec-out* %1)
:short #(.writeShort *spec-out* %1)
:int #(.writeInt *spec-out* %1)
:long #(.writeLong *spec-out* %1)
:byte #(.writeByte *spec-out* %1)
:short #(.writeShort *spec-out* %1)
:int #(.writeInt *spec-out* %1)
:long #(.writeLong *spec-out* %1)
:float #(.writeFloat *spec-out* %1)
:double #(.writeDouble *spec-out* %1)

:string write-pstring
:string write-pstring
})

; TODO: Make this complete
Expand Down Expand Up @@ -104,7 +132,7 @@
(declare spec-read)

(defn- spec-read-array [spec size]
;(println (str "[" (if (map? spec) (:name spec) spec) "] size = " size))
;;(println (str "[" (if (map? spec) (:name spec) spec) "] size = " size))
(loop [i size
ary []]
(if (pos? i)
Expand All @@ -120,21 +148,31 @@
[spec]
(loop [specs (:specs spec)
data {}]
;(println (str "spec-read - " (:name spec)))
;;(println (str "spec-read - " (:name spec)))
(if specs
(let [{:keys [fname ftype fdefault]} (first specs)
;_ (println (str ftype ": " fname " default: -" fdefault "-" ))
;;_ (println (str ftype ": " fname " default: -" fdefault "-" ))
fval (cond
; basic type
;; basic type
(contains? READERS ftype) ((ftype READERS))

; sub-spec
;; sub-spec
(map? ftype) (spec-read ftype)

; array
(vector? ftype) (spec-read-array (first ftype)
((keyword (str "n-" (name fname))) data)))]
;(println (str ftype ": " fname " <- " (if (vector? fval) (str "[" (:name (first ftype)) "]") fval)))
;; array or fstring
(vector? ftype)
(if (= :fstring (first ftype))
(read-fstring (second ftype))
(spec-read-array (first ftype)
(if (= 2 (count ftype))
(second ftype)
((keyword (str "n-" (name fname))) data))))

;; function
(fn? ftype) (ftype)
)]
#_(println (str ftype ": " fname " <- "
(if (vector? fval) (str fval) fval)))
(recur (next specs) (assoc data fname fval)))
data)))

Expand Down