[llvm-commits] CVS: llvm/lib/Support/Compressor.cpp
Reid Spencer
reid at x10sys.com
Mon Oct 4 10:45:54 PDT 2004
Changes in directory llvm/lib/Support:
Compressor.cpp updated: 1.3 -> 1.4
---
Log message:
Excise the ill-advised RLCOMP compression algorithm and simply leave the
previously temporary NULLCOMP implementation that merely copies the data
verbatim without compression. Also, don't warn if there's no compression
library as that is taken care of during configuration time.
---
Diffs of the changes: (+20 -159)
Index: llvm/lib/Support/Compressor.cpp
diff -u llvm/lib/Support/Compressor.cpp:1.3 llvm/lib/Support/Compressor.cpp:1.4
--- llvm/lib/Support/Compressor.cpp:1.3 Mon Oct 4 12:29:25 2004
+++ llvm/lib/Support/Compressor.cpp Mon Oct 4 12:45:44 2004
@@ -26,12 +26,6 @@
#include <zlib.h>
#endif
-#ifndef HAVE_BZIP2
-# ifndef HAVE_ZLIB
-# warning No compression library is available!!
-# endif
-#endif
-
namespace {
inline int getdata(char*& buffer, unsigned& size,
@@ -45,19 +39,13 @@
}
//===----------------------------------------------------------------------===//
-//=== RLCOMP - very simple run length compression scheme
-//=== The code below transforms the input into blocks that are either
-//=== compressed or not. Each block starts with a header byte that provides
-//=== the length of the block. Values < 128 are uncompressed, values >128
-//=== are compressed. The value 128 is illegal. Currently, the algorithm is
-//=== not completed and is #if'd out.
+//=== NULLCOMP - a compression like set of routines that just copies data
+//=== without doing any compression. This is provided so that if the
+//=== configured environment doesn't have a compression library the
+//=== program can still work, albeit using more data/memory.
//===----------------------------------------------------------------------===//
-enum {
- MAX_RLCOMP_OUT = 32768
-};
-
-struct RLCOMP_stream {
+struct NULLCOMP_stream {
// User provided fields
char* next_in;
unsigned avail_in;
@@ -66,110 +54,19 @@
// Information fields
uint64_t output_count; // Total count of output bytes
-
-#if 0
- // Algorithm fields
- unsigned block_len; // Length of current block
- unsigned compression; // State of compression 0=no, 1=yes, 2=indeterminate
- char buffer[128]; // compression buffer (not used for decompress)
- unsigned buflen; // bytes in compression buffer
- bool pending; // is data pending to be written
- char pending_data; // the pending data
- unsigned clen; // length of the compressed block
-#endif
};
-void RLCOMP_init(RLCOMP_stream* s) {
+void NULLCOMP_init(NULLCOMP_stream* s) {
s->output_count = 0;
-#if 0
- s->block_len = 0;
- s->compression = 2;
- s->buflen = 0;
- s->pending = false;
- s->pending_data = 0;
- s->clen = 0;
-#endif
-}
-
-inline bool RLCOMP_getchar(RLCOMP_stream* s, unsigned& data) {
-#if 0
- if (s->avail_in) {
- data = *s->next_in++;
- s->avail_in--;
- return true;
- }
-#endif
- return false;
-}
-
-inline bool RLCOMP_putchar(RLCOMP_stream* s, unsigned data) {
-#if 0
- if (s->avail_out) {
- *s->next_out++ = data;
- s->avail_out--;
- s->output_count++;
- return true;
- } else {
- s->pending = true;
- s->pending_data = data;
- return false;
- }
-#else
- return false;
-#endif
}
-bool RLCOMP_compress(RLCOMP_stream* s) {
- assert(s && "Invalid RLCOMP_stream");
+bool NULLCOMP_compress(NULLCOMP_stream* s) {
+ assert(s && "Invalid NULLCOMP_stream");
assert(s->next_in != 0);
assert(s->next_out != 0);
assert(s->avail_in >= 1);
assert(s->avail_out >= 1);
-#if 0
-
- // Handle pending data from the last time in
- if (s->pending) {
- RLCOMP_putchar(s,s->pending_data);
- s->pending = false;
- }
-
- unsigned c = 0;
- unsigned lastc = 0;
- // Handle the degenerate len=1 case
- if (!RLCOMP_getchar(s,lastc)) {
- RLCOMP_putchar(s,1);
- return RLCOMP_putchar(s,lastc);
- }
-
- while (RLCOMP_getchar(s,c)) {
- switch(s->compression) {
- case 0:
- if (lastc == c) {
- s->compression = 1;
- s->clen = 2 ;
- } else {
- if (!RLCOMP_putchar(s, c))
- return false;
- }
- break;
-
- case 1:
- if (lastc != c) {
- s->compression = 2;
- if (!RLCOMP_putchar(s, s->clen))
- return false;
- } else {
- s->clen++;
- }
- break;
-
- case 2:
- break;
- }
- lastc = c;
- }
-#endif
if (s->avail_out >= s->avail_in) {
::memcpy(s->next_out, s->next_in, s->avail_in);
s->output_count += s->avail_in;
@@ -187,49 +84,13 @@
}
}
-bool RLCOMP_decompress(RLCOMP_stream* s) {
- assert(s && "Invalid RLCOMP_stream");
+bool NULLCOMP_decompress(NULLCOMP_stream* s) {
+ assert(s && "Invalid NULLCOMP_stream");
assert(s->next_in != 0);
assert(s->next_out != 0);
assert(s->avail_in >= 1);
assert(s->avail_out >= 1);
-#if 0
- unsigned c = 0;
- while (RLCOMP_getchar(s,c)) {
- switch(s->compression) {
- case 0: // This is not a compressed block
- s->block_len--;
- if (!RLCOMP_putchar(s,c))
- return false;
- break;
-
- case 1: // This is a comperssed block
- while (s->block_len-- > 0)
- if (!RLCOMP_putchar(s,c))
- return false;
- break;
-
- case 2: // This is the length field
- if (c < 128) {
- s->compression = 0;
- s->block_len = c;
- } else {
- s->compression = 1;
- s->block_len = c - 128;
- }
- continue;
-
- default: // oops!
- throw std::string("Invalid compression state");
- }
- if (s->block_len <= 0)
- s->compression = 2;
- }
-
- if (s->repeat > 0)
- throw std::string("Invalid compression state");
-#endif
if (s->avail_out >= s->avail_in) {
::memcpy(s->next_out, s->next_in, s->avail_in);
s->output_count += s->avail_in;
@@ -247,7 +108,7 @@
}
}
-void RLCOMP_end(RLCOMP_stream* strm) {
+void NULLCOMP_end(NULLCOMP_stream* strm) {
}
}
@@ -275,7 +136,7 @@
bzdata.avail_in = size;
bzdata.next_out = 0;
bzdata.avail_out = 0;
- switch ( BZ2_bzCompressInit(&bzdata, 9, 0, 0) ) {
+ switch ( BZ2_bzCompressInit(&bzdata, 9, 0, 100) ) {
case BZ_CONFIG_ERROR: throw std::string("bzip2 library mis-compiled");
case BZ_PARAM_ERROR: throw std::string("Compressor internal error");
case BZ_MEM_ERROR: throw std::string("Out of memory");
@@ -365,10 +226,10 @@
}
case COMP_TYPE_SIMPLE: {
- RLCOMP_stream sdata;
+ NULLCOMP_stream sdata;
sdata.next_in = in;
sdata.avail_in = size;
- RLCOMP_init(&sdata);
+ NULLCOMP_init(&sdata);
if (0 != getdata(sdata.next_out, sdata.avail_out,cb,context)) {
throw std::string("Can't allocate output buffer");
@@ -377,14 +238,14 @@
*(sdata.next_out++) = COMP_TYPE_SIMPLE;
sdata.avail_out--;
- while (!RLCOMP_compress(&sdata)) {
+ while (!NULLCOMP_compress(&sdata)) {
if (0 != getdata(sdata.next_out, sdata.avail_out,cb,context)) {
throw std::string("Can't allocate output buffer");
}
}
result = sdata.output_count + 1;
- RLCOMP_end(&sdata);
+ NULLCOMP_end(&sdata);
break;
}
default:
@@ -494,23 +355,23 @@
}
case COMP_TYPE_SIMPLE: {
- RLCOMP_stream sdata;
+ NULLCOMP_stream sdata;
sdata.next_in = in;
sdata.avail_in = size - 1;
- RLCOMP_init(&sdata);
+ NULLCOMP_init(&sdata);
if (0 != getdata(sdata.next_out, sdata.avail_out,cb,context)) {
throw std::string("Can't allocate output buffer");
}
- while (!RLCOMP_decompress(&sdata)) {
+ while (!NULLCOMP_decompress(&sdata)) {
if (0 != getdata(sdata.next_out, sdata.avail_out,cb,context)) {
throw std::string("Can't allocate output buffer");
}
}
result = sdata.output_count;
- RLCOMP_end(&sdata);
+ NULLCOMP_end(&sdata);
break;
}
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