Add C DLL Example

README.md

@@ -4,3 +4,6 @@ Kdb+ Database Examples
 This repo contains associated code for the [kdb+ guides](http://www.timestored.com/kdb-guides) from TimeStored.com.
 
 If you find them useful, consider taking one of our [kdb+ Training Courses](http://www.timestored.com/kdb-training/).
+
+* Writing a [kdb C dll](http://www.timestored.com/kdb-guides/compile-load-c-dll) [Code](c-dll-example)
+* QUnit [Unit Testing kdb](http://www.timestored.com/kdb-guides/kdb-regression-unit-tests) [Code](qunit)

c-dll-example/comprun.bat

@@ -0,0 +1,3 @@
+CALL "C:\Program Files (x86)\Microsoft Visual Studio 10.0\VC\vcvarsall.bat" amd64 
+cl /LD /DKXVER=3 mymoving.c mymoving.def q.lib
+q load-functions.q

c-dll-example/k.h

@@ -0,0 +1,142 @@
+#ifndef KX
+#define KX
+typedef char*S,C;typedef unsigned char G;typedef short H;typedef int I;typedef long long J;typedef float E;typedef double F;typedef void V;
+#ifdef __cplusplus
+extern"C"{
+#endif
+#ifndef KXVER
+#error "Set KXVER=3 for kdb+3.0 or standalone c-api after 2011-04-20. Otherwise set KXVER=2"
+#endif
+#if KXVER>=3
+typedef struct k0{signed char m,a,t;C u;I r;union{G g;H h;I i;J j;E e;F f;S s;struct k0*k;struct{J n;G G0[1];};};}*K;
+typedef struct{G g[16];}U;
+#define kU(x) ((U*)kG(x))
+#define xU ((U*)xG)
+extern K ku(U),ktn(I,J),kpn(S,J);
+#define DO(n,x)	{J i=0,_i=(n);for(;i<_i;++i){x;}}
+#else
+typedef struct k0{I r;H t,u;union{G g;H h;I i;J j;E e;F f;S s;struct k0*k;struct{I n;G G0[1];};};}*K;
+extern K ktn(I,I),kpn(S,I);
+#define DO(n,x)	{I i=0,_i=(n);for(;i<_i;++i){x;}}
+#endif
+#ifdef __cplusplus
+}
+#endif
+//#include<string.h>
+// vector accessors, e.g. kF(x)[i] for float&datetime
+#define kG(x)	((x)->G0)
+#define kC(x)	kG(x)
+#define kH(x)	((H*)kG(x))
+#define kI(x)	((I*)kG(x))
+#define kJ(x)	((J*)kG(x))
+#define kE(x)	((E*)kG(x))
+#define kF(x)	((F*)kG(x))
+#define kS(x)	((S*)kG(x))
+#define kK(x)	((K*)kG(x))
+
+//      type bytes qtype     ctype  accessor
+#define KB 1  // 1 boolean   char   kG
+#define UU 2  // 16 guid     U      kU
+#define KG 4  // 1 byte      char   kG
+#define KH 5  // 2 short     short  kH
+#define KI 6  // 4 int       int    kI
+#define KJ 7  // 8 long      long   kJ
+#define KE 8  // 4 real      float  kE
+#define KF 9  // 8 float     double kF
+#define KC 10 // 1 char      char   kC
+#define KS 11 // * symbol    char*  kS
+
+#define KP 12 // 8 timestamp long   kJ (nanoseconds from 2000.01.01)
+#define KM 13 // 4 month     int    kI (months from 2000.01.01)
+#define KD 14 // 4 date      int    kI (days from 2000.01.01)
+
+#define KN 16 // 8 timespan  long   kJ (nanoseconds)
+#define KU 17 // 4 minute    int    kI
+#define KV 18 // 4 second    int    kI
+#define KT 19 // 4 time      int    kI (millisecond)
+
+#define KZ 15 // 8 datetime  double kF (DO NOT USE)
+
+// table,dict
+#define XT 98 //   x->k is XD
+#define XD 99 //   kK(x)[0] is keys. kK(x)[1] is values.
+
+#ifdef __cplusplus
+extern"C"{
+#endif
+extern I khpun(const S,I,const S,I),khpu(const S,I,const S),khp(const S,I),ymd(I,I,I),dj(I);extern V r0(K),sd0(I),m9(),kclose(I);extern S sn(S,I),ss(S);
+extern K ktj(I,J),ka(I),kb(I),kg(I),kh(I),ki(I),kj(J),ke(F),kf(F),kc(I),ks(S),kd(I),kz(F),kt(I),sd1(I,K(*)(I)),dl(V*f,I),
+ knk(I,...),kp(S),ja(K*,V*),js(K*,S),jk(K*,K),k(I,const S,...),xT(K),xD(K,K),ktd(K),r1(K),krr(const S),orr(const S),dot(K,K),b9(I,K),d9(K);
+#ifdef __cplusplus 
+}
+#endif
+
+// nulls(n?) and infinities(w?)
+#define nh ((I)0xFFFF8000)
+#define wh ((I)0x7FFF)
+#define ni ((I)0x80000000)
+#define wi ((I)0x7FFFFFFF)
+#define nj ((J)0x8000000000000000LL) 
+#define wj 0x7FFFFFFFFFFFFFFFLL
+#ifdef WIN32
+#define nf (log(-1.0))
+#define wf (-log(0.0))
+#define isnan _isnan
+#define finite _finite
+extern double log();
+#else  
+#define nf (0/0.0)
+#define wf (1/0.0)
+#define closesocket(x) close(x)
+#endif 
+
+// remove more clutter
+#define O printf
+#define R return
+#define Z static
+#define P(x,y) {if(x)R(y);}
+#define U(x) P(!(x),0)
+#define SW switch
+#define CS(n,x)	case n:x;break;
+#define CD default
+
+#define ZV Z V
+#define ZK Z K
+#define ZH Z H
+#define ZI Z I
+#define ZJ Z J
+#define ZE Z E
+#define ZF Z F
+#define ZC Z C
+#define ZS Z S
+
+#define K1(f) K f(K x)
+#define K2(f) K f(K x,K y)
+#define TX(T,x) (*(T*)((G*)(x)+8))
+#define xr x->r
+#define xt x->t
+#define xu x->u
+#define xn x->n
+#define xx xK[0]
+#define xy xK[1]
+#define xg TX(G,x)
+#define xh TX(H,x)
+#define xi TX(I,x)
+#define xj TX(J,x)
+#define xe TX(E,x)
+#define xf TX(F,x)
+#define xs TX(S,x)
+#define xk TX(K,x)
+#define xG x->G0
+#define xH ((H*)xG)
+#define xI ((I*)xG)
+#define xJ ((J*)xG)
+#define xE ((E*)xG)
+#define xF ((F*)xG)
+#define xS ((S*)xG)
+#define xK ((K*)xG)
+#define xC xG
+#define xB ((G*)xG)
+
+#endif
+

c-dll-example/load-functions.q

@@ -0,0 +1,8 @@
+ / from the DLL mymoving load the functions and assign to named variables
+ / The 2: is used for loading
+ / 2 at the end specifies the number of arguments
+mysum:`mymoving 2:(`mysum;2)
+myavg:`mymoving 2:(`myavg;2)
+
+show "myavg[3; 6 7 5 8 2.]";
+myavg[3; 6 7 5 8 2.]

c-dll-example/mymoving.c

@@ -0,0 +1,75 @@
+// TimeStored.com example of windows DLL
+// http://www.timestored.com/kdb-guides/compile-load-c-dll
+
+#include"k.h"
+#include <float.h>
+
+// Find the moving sum for a given window size and array of nums
+K mysum(K window, K nums) {
+
+	long wsize = window->j;
+	long i=0;
+	K res = ktn(KF, nums->n);
+	double total;
+
+	F* resf = kF(res);
+	F* numsf = kF(nums);
+
+	// check type is float
+	if( (nums->t != KF) || (window->t != -KJ)) {
+		printf("invalid params");
+		return krr("wrong type params");
+	}
+
+	total = numsf[0];
+	resf[0] = total;
+	for(i=1; i < wsize; i++) {
+		total += numsf[i];
+		resf[i]=total;
+	}
+
+	for(i=wsize; i < nums->n; i++) {
+		total = total - numsf[i-wsize]+numsf[i];
+		resf[i]=total;
+	}
+
+	return res;
+} 
+
+
+// Find the moving average for a given window size and array of nums
+K myavg(K window, K nums) {
+
+	// initialize variables
+	long wsize = window->j;
+	long i=0;
+	K res = ktn(KF, nums->n);
+	double total;
+	long count;
+
+	F* resf = kF(res);
+	F* numsf = kF(nums);
+
+	// check type is float
+	if( (nums->t != KF) || (window->t != -KJ)) {
+		printf("invalid params");
+		return krr("wrong type params");
+	}
+
+	// find moving average of first window (special case)
+	total = numsf[0];
+	resf[0] = total;
+	count = 2;
+	for(i=1; i < wsize; i++) {
+		total += numsf[i];
+		resf[i] = total / count++;
+	}
+
+	// move window along by adding next number and removing earliest from average.
+	for(i=wsize; i < nums->n; i++) {
+		total = total - numsf[i-wsize]+numsf[i];
+		resf[i] = total / wsize;
+	}
+
+	return res;
+} 

c-dll-example/mymoving.def

@@ -0,0 +1,3 @@
+EXPORTS
+mysum
+myavg

c-dll-example/readme.md

@@ -0,0 +1,11 @@
+Calling C code from kdb+
+======================================
+
+The code demonstrates [compiling and loading a c dll for kdb](http://www.timestored.com/kdb-guides/compile-load-c-dll).
+
+It shows how to:
+ - Compile a DLL on windows
+ - Load the library within kdb
+ - Calling the C function from kdb
+
+It is a simple example only and does not contain good logging, argument checking etc.