Code refactored. Auto-rebuild feature

Makefile

@@ -1,20 +1,36 @@
 CC=gcc
-CFLAGS=-O3 -lz
-TARGETS=seekgzip
-PYTHON_TARGETS=export_python.cpp seekgzip.py
+SWIG=swig
+PYTHON=python
 
-all: $(TARGETS)
+LDFLAGS=-lz
+
+USR_BIN_TARGETS=seekgzip
+USR_LIB_TARGETS=libseekgzip.so
+USR_INC_TARGETS=seekgzip.h
+PHONY_TARGETS=.python
 
+TARGETS=$(USR_BIN_TARGETS) $(USR_LIB_TARGETS) $(PHONY_TARGETS)
+
+all: $(TARGETS)
 clean:
-	rm $(TARGETS)
+	rm -rf $(TARGETS)
+	rm -rf export_python.cpp
+
+install:
+	mkdir -p $(DESTDIR)/$(EPREFIX)/usr/bin/ $(DESTDIR)/$(EPREFIX)/usr/lib/ $(DESTDIR)/$(EPREFIX)/usr/include/seekgzip/
+	cp $(USR_BIN_TARGETS) $(DESTDIR)/$(EPREFIX)/usr/bin/
+	cp $(USR_LIB_TARGETS) $(DESTDIR)/$(EPREFIX)/usr/lib/
+	cp $(USR_INC_TARGETS) $(DESTDIR)/$(EPREFIX)/usr/include/seekgzip/
+	test -f .python && $(PYTHON) setup.py install || exit 0
 
-python: $(PYTHON_TARGETS)
+seekgzip: seekgzip.c main.c
+	$(CC) $(CFLAGS) $(LDFLAGS) -o $@ seekgzip.c main.c
 
-clean-python:
-	rm $(PYTHON_TARGETS)
+libseekgzip.so: seekgzip.c
+	$(CC) $(CFLAGS) $(LDFLAGS) -fPIC -shared -o $@ $<
 
-seekgzip: seekgzip.c
-	$(CC) $(CFLAGS) -o $@ -DBUILD_UTILITY $<
+.python: swig.i export_cpp.h export_cpp.cpp setup.py
+	$(SWIG) -c++ -python -o export_python.cpp swig.i
+	$(PYTHON) setup.py build
+	touch $@
 
-$(PYTHON_TARGETS): export.h export.i
-	swig -c++ -python -o export_python.cpp export.i

README

@@ -18,8 +18,10 @@ streams.
 
 
 * HOW TO BUILD THE UTILITY
-$ make
+$ make all
 
+* HOW TO INSTALL THE UTILITY
+$ make install
 
 * HOW TO USE THE UTILITY
 
@@ -29,17 +31,11 @@ This builds an index file for the specified gzip file ${FILE}. This
 utility creates an index file ${FILE}.idx
 
 (2) Reading the data in the specified range
-$ seekgzip <FILE> [BEGIN:END]
+$ seekgzip <FILE> [BEGIN-END]
 This reads the data in the gzip file ${FILE} from the offset ${BEGIN}
 to ${END}, and outputs the data to STDOUT.
 
 
-* HOW TO BUILD PYTHON MODULE
-$ make python
-$ python setup.py --build_ext
-$ python setup.py install
-
-
 * COPYRIGHT AND LICENSING INFORMATION
 
 This program is distributed under the zlib license.

export.cpp → export_cpp.cpp

@@ -1,7 +1,7 @@
 #include <string>
 #include <stdexcept>
 #include "seekgzip.h"
-#include "export.h"
+#include "export_cpp.h"
 
 static std::string error_string(int errorcode)
 {
@@ -31,9 +31,9 @@ static std::string error_string(int errorcode)
 reader::reader(const char *filename)
 {
     int err = 0;
-    seekgzip_t* sgz = seekgzip_open(filename, &err);
+    seekgzip_t* sgz = seekgzip_open(filename, 0);
     m_obj = sgz;
-    if (sgz == NULL) {
+    if ( (err = seekgzip_error(sgz)) != SEEKGZIP_SUCCESS){
         throw std::invalid_argument(error_string(err));
     }
 }

main.c

@@ -0,0 +1,135 @@
+/*
+ *		SeekGzip utility/library.
+ *
+ * Copyright (c) 2010-2011, Naoaki Okazaki
+ * All rights reserved.
+ * 
+ * For conditions of distribution and use, see copyright notice in README
+ * or zlib.h.
+ * 
+ * The core algorithm for random access originates from zran.c in zlib/gzip
+ * distribution. This code simply implements a data structure and algorithm
+ * for indices, wraps the functionality of random access as a library, and
+ * provides a command-line utility.
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdint.h>
+#include <string.h>
+#include "seekgzip.h"
+
+#define CHUNK 16384		 /* file input buffer size */
+
+static void seekgzip_perror(int ret)
+{
+	switch (ret) {
+	case SEEKGZIP_ERROR:
+		fprintf(stderr, "ERROR: An unknown error occurred.\n");
+		break;
+	case SEEKGZIP_OPENERROR:
+		fprintf(stderr, "ERROR: Failed to open a file.\n");
+		break;
+	case SEEKGZIP_READERROR:
+		fprintf(stderr, "ERROR: Failed to read a file.\n");
+		break;
+	case SEEKGZIP_WRITEERROR:
+		fprintf(stderr, "ERROR: Failed to write a file.\n");
+		break;
+	case SEEKGZIP_DATAERROR:
+		fprintf(stderr, "ERROR: The file is corrupted.\n");
+		break;
+	case SEEKGZIP_OUTOFMEMORY:
+		fprintf(stderr, "ERROR: Out of memory.\n");
+		break;
+	case SEEKGZIP_IMCOMPATIBLE:
+		fprintf(stderr, "ERROR: The imcompatible file.\n");
+		break;
+	case SEEKGZIP_ZLIBERROR:
+		fprintf(stderr, "ERROR: An error occurred in zlib.\n");
+		break;
+	}
+}
+
+int main(int argc, char *argv[])
+{
+	int ret = 0;
+
+	if (argc != 3) {
+		printf("This utility manages an index for random (seekable) access to a gzip file.\n");
+		printf("USAGE:\n");
+		printf("	%s -b <FILE>\n", argv[0]);
+		printf("		Build an index file \"$FILE.idx\" for the gzip file $FILE.\n");
+		printf("	%s <FILE> [BEGIN-END]\n", argv[0]);
+		printf("		Output the content of the gzip file $FILE of offset range [BEGIN-END].\n");
+		return 0;
+
+	} else if (strcmp(argv[1], "-b") == 0) {
+		const char *target = argv[2];
+
+		printf("Building an index: %s.idx\n", target);
+		printf("Filesize up to: %d bit\n", (int)sizeof(off_t) * 8);
+		printf("WARNING: if program fail to write index to file, it would silently ignore that\n");
+
+		seekgzip_t* zs = seekgzip_open(target, 0);
+		if ((ret = seekgzip_error(zs)) != SEEKGZIP_SUCCESS) {
+			seekgzip_perror(ret);
+			return 1;
+		}
+		seekgzip_close(zs);
+	return 0;
+
+	} else {
+		char *arg = argv[2], *p = NULL;
+		off_t begin = 0, end = (off_t)-1;
+		seekgzip_t* zs = seekgzip_open(argv[1], 0);
+		if (zs == NULL || seekgzip_error(zs) != SEEKGZIP_SUCCESS) {
+			fprintf(stderr, "ERROR: Failed to open the index file.\n");
+			return 1;
+		}
+
+		p = strchr(arg, '-');
+		if (p == NULL) {
+			begin =(off_t)strtoull(arg, NULL, 10);
+			end = begin+1;
+		} else if (p == arg) {
+			begin = 0;
+			end = (off_t)strtoull(p+1, NULL, 10);
+		} else if (p == arg + strlen(arg) - 1) {
+			*p = 0;
+			begin = (off_t)strtoull(arg, NULL, 10);
+		} else {
+			*p++ = 0;
+			begin =(off_t)strtoull(arg, NULL, 10);
+			end =(off_t)strtoull(p, NULL, 10);
+		}
+
+		seekgzip_seek(zs, begin);
+
+		while (begin < end) {
+			int read;
+			char buffer[CHUNK];
+			off_t size = (end - begin);
+			if (CHUNK < size) {
+				size = CHUNK;
+			}
+			read = seekgzip_read(zs, buffer, (int)size);
+			if (0 < read) {
+				begin += read;
+
+		if(fwrite(buffer, read, sizeof(char), stdout) == 0)
+			continue;
+			} else if (read == 0) {
+				break;
+			} else {
+				fprintf(stderr, "ERROR: An error occurred while reading the gzip file.\n");
+				ret = 1;
+				break;
+			}
+		}
+
+		seekgzip_close(zs);
+		return ret;
+	}
+}
+