Refactor tjbench.c to provide test interface

tjbench.c contains a program to benchmark encoding and decoding of
JPEG images. As such, the code in tjbench.c was designed to run as
a stanalone binary. As well as benchmarking code, tjbench is used
to produce image data for unit test input.

This commit refactors tjbench.c to provide an interface to run the
tjbench code programmatically. A gtest wrapper containing unit tests
will be introduced in a subsequent commit.

All other global symbols in tjbench.c are marked as 'static' to
prevent symbol collision.

Bug: 993876
Change-Id: Ib8469d4ee8adee466f0b9d8a9dd696bd5ef7c205

2 files changed, 32 insertions, 24 deletions

diff --git a/README.chromium b/README.chromium
index 267d456..0b29019 100644
--- a/README.chromium
+++ b/README.chromium
@@ -74,6 +74,7 @@ following changes which are not merged to upstream:
   - Refactor tjunittest.c to provide test interface
   - Add gtest wrapper for tjunittests
   - Move tjunittest logs from stdout to stderr
+  - Refactor tjbench.c to provide test interface
 
 Refer to working-with-nested-repos [1] for details of how to setup your git
 svn client to update the code (for making local changes, cherry picking from
diff --git a/tjbench.c b/tjbench.c
index 863e534..94a0c5e 100644
--- a/tjbench.c
+++ b/tjbench.c
@@ -43,8 +43,9 @@
 }
 #define _throwunix(m)  _throw(m, strerror(errno))
 
-char tjErrorStr[JMSG_LENGTH_MAX] = "\0", tjErrorMsg[JMSG_LENGTH_MAX] = "\0";
-int tjErrorLine = -1, tjErrorCode = -1;
+static char tjErrorStr[JMSG_LENGTH_MAX] = "\0",
+            tjErrorMsg[JMSG_LENGTH_MAX] = "\0";
+static int tjErrorLine = -1, tjErrorCode = -1;
 
 #define _throwtjg(m) { \
   printf("ERROR in line %d while %s:\n%s\n", __LINE__, m, \
@@ -74,28 +75,29 @@ int tjErrorLine = -1, tjErrorCode = -1;
   } \
 }
 
-int flags = TJFLAG_NOREALLOC, compOnly = 0, decompOnly = 0, doYUV = 0,
+static int flags = TJFLAG_NOREALLOC, compOnly = 0, decompOnly = 0, doYUV = 0,
   quiet = 0, doTile = 0, pf = TJPF_BGR, yuvPad = 1, doWrite = 1;
-char *ext = "ppm";
-const char *pixFormatStr[TJ_NUMPF] = {
+static char *ext = "ppm";
+static const char *pixFormatStr[TJ_NUMPF] = {
   "RGB", "BGR", "RGBX", "BGRX", "XBGR", "XRGB", "GRAY", "", "", "", "", "CMYK"
 };
-const char *subNameLong[TJ_NUMSAMP] = {
+static const char *subNameLong[TJ_NUMSAMP] = {
   "4:4:4", "4:2:2", "4:2:0", "GRAY", "4:4:0", "4:1:1"
 };
-const char *csName[TJ_NUMCS] = {
+static const char *csName[TJ_NUMCS] = {
   "RGB", "YCbCr", "GRAY", "CMYK", "YCCK"
 };
-const char *subName[TJ_NUMSAMP] = {
+static const char *subName[TJ_NUMSAMP] = {
   "444", "422", "420", "GRAY", "440", "411"
 };
-tjscalingfactor *scalingFactors = NULL, sf = { 1, 1 };
-int nsf = 0, xformOp = TJXOP_NONE, xformOpt = 0;
-int (*customFilter) (short *, tjregion, tjregion, int, int, tjtransform *);
-double benchTime = 5.0, warmup = 1.0;
+static tjscalingfactor *scalingFactors = NULL, sf = { 1, 1 };
+static int nsf = 0, xformOp = TJXOP_NONE, xformOpt = 0;
+static int (*customFilter) (short *, tjregion, tjregion, int, int,
+                            tjtransform *);
+static double benchTime = 5.0, warmup = 1.0;
 
 
-char *formatName(int subsamp, int cs, char *buf)
+static char *formatName(int subsamp, int cs, char *buf)
 {
   if (cs == TJCS_YCbCr)
     return (char *)subNameLong[subsamp];
@@ -107,7 +109,7 @@ char *formatName(int subsamp, int cs, char *buf)
 }
 
 
-char *sigfig(double val, int figs, char *buf, int len)
+static char *sigfig(double val, int figs, char *buf, int len)
 {
   char format[80];
   int digitsAfterDecimal = figs - (int)ceil(log10(fabs(val)));
@@ -122,9 +124,9 @@ char *sigfig(double val, int figs, char *buf, int len)
 
 
 /* Custom DCT filter which produces a negative of the image */
-int dummyDCTFilter(short *coeffs, tjregion arrayRegion, tjregion planeRegion,
-                   int componentIndex, int transformIndex,
-                   tjtransform *transform)
+static int dummyDCTFilter(short *coeffs, tjregion arrayRegion,
+                          tjregion planeRegion, int componentIndex,
+                          int transformIndex, tjtransform *transform)
 {
   int i;
 
@@ -135,9 +137,10 @@ int dummyDCTFilter(short *coeffs, tjregion arrayRegion, tjregion planeRegion,
 
 
 /* Decompression test */
-int decomp(unsigned char *srcBuf, unsigned char **jpegBuf,
-           unsigned long *jpegSize, unsigned char *dstBuf, int w, int h,
-           int subsamp, int jpegQual, char *fileName, int tilew, int tileh)
+static int decomp(unsigned char *srcBuf, unsigned char **jpegBuf,
+                  unsigned long *jpegSize, unsigned char *dstBuf, int w, int h,
+                  int subsamp, int jpegQual, char *fileName, int tilew,
+                  int tileh)
 {
   char tempStr[1024], sizeStr[20] = "\0", qualStr[6] = "\0", *ptr;
   FILE *file = NULL;
@@ -303,8 +306,8 @@ bailout:
 }
 
 
-int fullTest(unsigned char *srcBuf, int w, int h, int subsamp, int jpegQual,
-             char *fileName)
+static int fullTest(unsigned char *srcBuf, int w, int h, int subsamp,
+                    int jpegQual, char *fileName)
 {
   char tempStr[1024], tempStr2[80];
   FILE *file = NULL;
@@ -504,7 +507,7 @@ bailout:
 }
 
 
-int decompTest(char *fileName)
+static int decompTest(char *fileName)
 {
   FILE *file = NULL;
   tjhandle handle = NULL;
@@ -722,7 +725,7 @@ bailout:
 }
 
 
-void usage(char *progName)
+static void usage(char *progName)
 {
   int i;
 
@@ -793,7 +796,11 @@ void usage(char *progName)
 }
 
 
+#ifndef GTEST
 int main(int argc, char *argv[])
+#else
+int tjbench(int argc, char *argv[])
+#endif
 {
   unsigned char *srcBuf = NULL;
   int w = 0, h = 0, i, j, minQual = -1, maxQual = -1;