1 files changed, 490 insertions, 0 deletions

diff --git a/utils/rbutilqt/mspack/qtmd.c b/utils/rbutilqt/mspack/qtmd.c
new file mode 100644
index 0000000000..58e4787b7f
--- /dev/null
+++ b/utils/rbutilqt/mspack/qtmd.c
@@ -0,0 +1,490 @@
+/* This file is part of libmspack.
+ * (C) 2003-2004 Stuart Caie.
+ *
+ * The Quantum method was created by David Stafford, adapted by Microsoft
+ * Corporation.
+ *
+ * This decompressor is based on an implementation by Matthew Russotto, used
+ * with permission.
+ *
+ * libmspack is free software; you can redistribute it and/or modify it under
+ * the terms of the GNU Lesser General Public License (LGPL) version 2.1
+ *
+ * For further details, see the file COPYING.LIB distributed with libmspack
+ */
+
+/* Quantum decompression implementation */
+
+/* This decompressor was researched and implemented by Matthew Russotto. It
+ * has since been tidied up by Stuart Caie. More information can be found at
+ * http://www.speakeasy.org/~russotto/quantumcomp.html
+ */
+
+#include "system-mspack.h"
+#include "qtm.h"
+
+/* import bit-reading macros and code */
+#define BITS_TYPE struct qtmd_stream
+#define BITS_VAR qtm
+#define BITS_ORDER_MSB
+#define READ_BYTES do {                 \
+    unsigned char b0, b1;               \
+    READ_IF_NEEDED; b0 = *i_ptr++;      \
+    READ_IF_NEEDED; b1 = *i_ptr++;      \
+    INJECT_BITS((b0 << 8) | b1, 16);    \
+} while (0)
+#include "readbits.h"
+
+/* Quantum static data tables:
+ *
+ * Quantum uses 'position slots' to represent match offsets.  For every
+ * match, a small 'position slot' number and a small offset from that slot
+ * are encoded instead of one large offset.
+ *
+ * position_base[] is an index to the position slot bases
+ *
+ * extra_bits[] states how many bits of offset-from-base data is needed.
+ *
+ * length_base[] and length_extra[] are equivalent in function, but are
+ * used for encoding selector 6 (variable length match) match lengths,
+ * instead of match offsets.
+ *
+ * They are generated with the following code:
+ *   unsigned int i, offset;
+ *   for (i = 0, offset = 0; i < 42; i++) {
+ *     position_base[i] = offset;
+ *     extra_bits[i] = ((i < 2) ? 0 : (i - 2)) >> 1;
+ *     offset += 1 << extra_bits[i];
+ *   }
+ *   for (i = 0, offset = 0; i < 26; i++) {
+ *     length_base[i] = offset;
+ *     length_extra[i] = (i < 2 ? 0 : i - 2) >> 2;
+ *     offset += 1 << length_extra[i];
+ *   }
+ *   length_base[26] = 254; length_extra[26] = 0;
+ */
+static const unsigned int position_base[42] = {
+  0, 1, 2, 3, 4, 6, 8, 12, 16, 24, 32, 48, 64, 96, 128, 192, 256, 384, 512, 768,
+  1024, 1536, 2048, 3072, 4096, 6144, 8192, 12288, 16384, 24576, 32768, 49152,
+  65536, 98304, 131072, 196608, 262144, 393216, 524288, 786432, 1048576, 1572864
+};
+static const unsigned char extra_bits[42] = {
+  0, 0, 0, 0, 1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 6, 7, 7, 8, 8, 9, 9, 10, 10,
+  11, 11, 12, 12, 13, 13, 14, 14, 15, 15, 16, 16, 17, 17, 18, 18, 19, 19
+};
+static const unsigned char length_base[27] = {
+  0, 1, 2, 3, 4, 5, 6, 8, 10, 12, 14, 18, 22, 26,
+  30, 38, 46, 54, 62, 78, 94, 110, 126, 158, 190, 222, 254
+};
+static const unsigned char length_extra[27] = {
+  0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 2, 2, 2, 2,
+  3, 3, 3, 3, 4, 4, 4, 4, 5, 5, 5, 5, 0
+};
+
+
+/* Arithmetic decoder:
+ * 
+ * GET_SYMBOL(model, var) fetches the next symbol from the stated model
+ * and puts it in var.
+ *
+ * If necessary, qtmd_update_model() is called.
+ */
+#define GET_SYMBOL(model, var) do {                                     \
+  range = ((H - L) & 0xFFFF) + 1;                                       \
+  symf = ((((C - L + 1) * model.syms[0].cumfreq)-1) / range) & 0xFFFF;  \
+                                                                        \
+  for (i = 1; i < model.entries; i++) {                                 \
+    if (model.syms[i].cumfreq <= symf) break;                           \
+  }                                                                     \
+  (var) = model.syms[i-1].sym;                                          \
+                                                                        \
+  range = (H - L) + 1;                                                  \
+  symf = model.syms[0].cumfreq;                                         \
+  H = L + ((model.syms[i-1].cumfreq * range) / symf) - 1;               \
+  L = L + ((model.syms[i].cumfreq   * range) / symf);                   \
+                                                                        \
+  do { model.syms[--i].cumfreq += 8; } while (i > 0);                   \
+  if (model.syms[0].cumfreq > 3800) qtmd_update_model(&model);          \
+                                                                        \
+  while (1) {                                                           \
+    if ((L & 0x8000) != (H & 0x8000)) {                                 \
+      if ((L & 0x4000) && !(H & 0x4000)) {                              \
+        /* underflow case */                                            \
+        C ^= 0x4000; L &= 0x3FFF; H |= 0x4000;                          \
+      }                                                                 \
+      else break;                                                       \
+    }                                                                   \
+    L <<= 1; H = (H << 1) | 1;                                          \
+    ENSURE_BITS(1);                                                     \
+    C  = (C << 1) | PEEK_BITS(1);                                       \
+    REMOVE_BITS(1);                                                     \
+  }                                                                     \
+} while (0)
+
+static void qtmd_update_model(struct qtmd_model *model) {
+  struct qtmd_modelsym tmp;
+  int i, j;
+
+  if (--model->shiftsleft) {
+    for (i = model->entries - 1; i >= 0; i--) {
+      /* -1, not -2; the 0 entry saves this */
+      model->syms[i].cumfreq >>= 1;
+      if (model->syms[i].cumfreq <= model->syms[i+1].cumfreq) {
+        model->syms[i].cumfreq = model->syms[i+1].cumfreq + 1;
+      }
+    }
+  }
+  else {
+    model->shiftsleft = 50;
+    for (i = 0; i < model->entries; i++) {
+      /* no -1, want to include the 0 entry */
+      /* this converts cumfreqs into frequencies, then shifts right */
+      model->syms[i].cumfreq -= model->syms[i+1].cumfreq;
+      model->syms[i].cumfreq++; /* avoid losing things entirely */
+      model->syms[i].cumfreq >>= 1;
+    }
+
+    /* now sort by frequencies, decreasing order -- this must be an
+     * inplace selection sort, or a sort with the same (in)stability
+     * characteristics */
+    for (i = 0; i < model->entries - 1; i++) {
+      for (j = i + 1; j < model->entries; j++) {
+        if (model->syms[i].cumfreq < model->syms[j].cumfreq) {
+          tmp = model->syms[i];
+          model->syms[i] = model->syms[j];
+          model->syms[j] = tmp;
+        }
+      }
+    }
+
+    /* then convert frequencies back to cumfreq */
+    for (i = model->entries - 1; i >= 0; i--) {
+      model->syms[i].cumfreq += model->syms[i+1].cumfreq;
+    }
+  }
+}
+
+/* Initialises a model to decode symbols from [start] to [start]+[len]-1 */
+static void qtmd_init_model(struct qtmd_model *model,
+                            struct qtmd_modelsym *syms, int start, int len)
+{
+  int i;
+
+  model->shiftsleft = 4;
+  model->entries    = len;
+  model->syms       = syms;
+
+  for (i = 0; i <= len; i++) {
+    syms[i].sym     = start + i; /* actual symbol */
+    syms[i].cumfreq = len - i;   /* current frequency of that symbol */
+  }
+}
+
+
+/*-------- main Quantum code --------*/
+
+struct qtmd_stream *qtmd_init(struct mspack_system *system,
+                              struct mspack_file *input,
+                              struct mspack_file *output,
+                              int window_bits, int input_buffer_size)
+{
+  unsigned int window_size = 1 << window_bits;
+  struct qtmd_stream *qtm;
+  int i;
+
+  if (!system) return NULL;
+
+  /* Quantum supports window sizes of 2^10 (1Kb) through 2^21 (2Mb) */
+  if (window_bits < 10 || window_bits > 21) return NULL;
+
+  /* round up input buffer size to multiple of two */
+  input_buffer_size = (input_buffer_size + 1) & -2;
+  if (input_buffer_size < 2) return NULL;
+
+  /* allocate decompression state */
+  if (!(qtm = (struct qtmd_stream *) system->alloc(system, sizeof(struct qtmd_stream)))) {
+    return NULL;
+  }
+
+  /* allocate decompression window and input buffer */
+  qtm->window = (unsigned char *) system->alloc(system, (size_t) window_size);
+  qtm->inbuf  = (unsigned char *) system->alloc(system, (size_t) input_buffer_size);
+  if (!qtm->window || !qtm->inbuf) {
+    system->free(qtm->window);
+    system->free(qtm->inbuf);
+    system->free(qtm);
+    return NULL;
+  }
+
+  /* initialise decompression state */
+  qtm->sys         = system;
+  qtm->input       = input;
+  qtm->output      = output;
+  qtm->inbuf_size  = input_buffer_size;
+  qtm->window_size = window_size;
+  qtm->window_posn = 0;
+  qtm->frame_todo  = QTM_FRAME_SIZE;
+  qtm->header_read = 0;
+  qtm->error       = MSPACK_ERR_OK;
+
+  qtm->i_ptr = qtm->i_end = &qtm->inbuf[0];
+  qtm->o_ptr = qtm->o_end = &qtm->window[0];
+  qtm->input_end = 0;
+  qtm->bits_left = 0;
+  qtm->bit_buffer = 0;
+
+  /* initialise arithmetic coding models
+   * - model 4    depends on window size, ranges from 20 to 24
+   * - model 5    depends on window size, ranges from 20 to 36
+   * - model 6pos depends on window size, ranges from 20 to 42
+   */
+  i = window_bits * 2;
+  qtmd_init_model(&qtm->model0,    &qtm->m0sym[0],   0, 64);
+  qtmd_init_model(&qtm->model1,    &qtm->m1sym[0],  64, 64);
+  qtmd_init_model(&qtm->model2,    &qtm->m2sym[0], 128, 64);
+  qtmd_init_model(&qtm->model3,    &qtm->m3sym[0], 192, 64);
+  qtmd_init_model(&qtm->model4,    &qtm->m4sym[0],   0, (i > 24) ? 24 : i);
+  qtmd_init_model(&qtm->model5,    &qtm->m5sym[0],   0, (i > 36) ? 36 : i);
+  qtmd_init_model(&qtm->model6,    &qtm->m6sym[0],   0, i);
+  qtmd_init_model(&qtm->model6len, &qtm->m6lsym[0],  0, 27);
+  qtmd_init_model(&qtm->model7,    &qtm->m7sym[0],   0, 7);
+
+  /* all ok */
+  return qtm;
+}
+
+int qtmd_decompress(struct qtmd_stream *qtm, off_t out_bytes) {
+  unsigned int frame_todo, frame_end, window_posn, match_offset, range;
+  unsigned char *window, *i_ptr, *i_end, *runsrc, *rundest;
+  int i, j, selector, extra, sym, match_length;
+  unsigned short H, L, C, symf;
+
+  register unsigned int bit_buffer;
+  register unsigned char bits_left;
+
+  /* easy answers */
+  if (!qtm || (out_bytes < 0)) return MSPACK_ERR_ARGS;
+  if (qtm->error) return qtm->error;
+
+  /* flush out any stored-up bytes before we begin */
+  i = qtm->o_end - qtm->o_ptr;
+  if ((off_t) i > out_bytes) i = (int) out_bytes;
+  if (i) {
+    if (qtm->sys->write(qtm->output, qtm->o_ptr, i) != i) {
+      return qtm->error = MSPACK_ERR_WRITE;
+    }
+    qtm->o_ptr  += i;
+    out_bytes   -= i;
+  }
+  if (out_bytes == 0) return MSPACK_ERR_OK;
+
+  /* restore local state */
+  RESTORE_BITS;
+  window = qtm->window;
+  window_posn = qtm->window_posn;
+  frame_todo = qtm->frame_todo;
+  H = qtm->H;
+  L = qtm->L;
+  C = qtm->C;
+
+  /* while we do not have enough decoded bytes in reserve: */
+  while ((qtm->o_end - qtm->o_ptr) < out_bytes) {
+    /* read header if necessary. Initialises H, L and C */
+    if (!qtm->header_read) {
+      H = 0xFFFF; L = 0; READ_BITS(C, 16);
+      qtm->header_read = 1;
+    }
+
+    /* decode more, up to the number of bytes needed, the frame boundary,
+     * or the window boundary, whichever comes first */
+    frame_end = window_posn + (out_bytes - (qtm->o_end - qtm->o_ptr));
+    if ((window_posn + frame_todo) < frame_end) {
+      frame_end = window_posn + frame_todo;
+    }
+    if (frame_end > qtm->window_size) {
+      frame_end = qtm->window_size;
+    }
+
+    while (window_posn < frame_end) {
+      GET_SYMBOL(qtm->model7, selector);
+      if (selector < 4) {
+        /* literal byte */
+        struct qtmd_model *mdl = (selector == 0) ? &qtm->model0 :
+                                ((selector == 1) ? &qtm->model1 :
+                                ((selector == 2) ? &qtm->model2 :
+                                                   &qtm->model3));
+        GET_SYMBOL((*mdl), sym);
+        window[window_posn++] = sym;
+        frame_todo--;
+      }
+      else {
+        /* match repeated string */
+        switch (selector) {
+        case 4: /* selector 4 = fixed length match (3 bytes) */
+          GET_SYMBOL(qtm->model4, sym);
+          READ_MANY_BITS(extra, extra_bits[sym]);
+          match_offset = position_base[sym] + extra + 1;
+          match_length = 3;
+          break;
+
+        case 5: /* selector 5 = fixed length match (4 bytes) */
+          GET_SYMBOL(qtm->model5, sym);
+          READ_MANY_BITS(extra, extra_bits[sym]);
+          match_offset = position_base[sym] + extra + 1;
+          match_length = 4;
+          break;
+
+        case 6: /* selector 6 = variable length match */
+          GET_SYMBOL(qtm->model6len, sym);
+          READ_MANY_BITS(extra, length_extra[sym]);
+          match_length = length_base[sym] + extra + 5;
+
+          GET_SYMBOL(qtm->model6, sym);
+          READ_MANY_BITS(extra, extra_bits[sym]);
+          match_offset = position_base[sym] + extra + 1;
+          break;
+
+        default:
+          /* should be impossible, model7 can only return 0-6 */
+          D(("got %d from selector", selector))
+          return qtm->error = MSPACK_ERR_DECRUNCH;
+        }
+
+        rundest = &window[window_posn];
+        frame_todo -= match_length;
+
+        /* does match destination wrap the window? This situation is possible
+         * where the window size is less than the 32k frame size, but matches
+         * must not go beyond a frame boundary */
+        if ((window_posn + match_length) > qtm->window_size) {
+          /* copy first part of match, before window end */
+          i = qtm->window_size - window_posn;
+          j = window_posn - match_offset;
+          while (i--) *rundest++ = window[j++ & (qtm->window_size - 1)];
+
+          /* flush currently stored data */
+          i = (&window[qtm->window_size] - qtm->o_ptr);
+
+          /* this should not happen, but if it does then this code
+           * can't handle the situation (can't flush up to the end of
+           * the window, but can't break out either because we haven't
+           * finished writing the match). bail out in this case */
+          if (i > out_bytes) {
+            D(("during window-wrap match; %d bytes to flush but only need %d",
+               i, (int) out_bytes))
+            return qtm->error = MSPACK_ERR_DECRUNCH;
+          }
+          if (qtm->sys->write(qtm->output, qtm->o_ptr, i) != i) {
+            return qtm->error = MSPACK_ERR_WRITE;
+          }
+          out_bytes -= i;
+          qtm->o_ptr = &window[0];
+          qtm->o_end = &window[0]; 
+
+          /* copy second part of match, after window wrap */
+          rundest = &window[0];
+          i = match_length - (qtm->window_size - window_posn);
+          while (i--) *rundest++ = window[j++ & (qtm->window_size - 1)];
+          window_posn = window_posn + match_length - qtm->window_size;
+
+          break; /* because "window_posn < frame_end" has now failed */
+        }
+        else {
+          /* normal match - output won't wrap window or frame end */
+          i = match_length;
+
+          /* does match _offset_ wrap the window? */
+          if (match_offset > window_posn) {
+            /* j = length from match offset to end of window */
+            j = match_offset - window_posn;
+            if (j > (int) qtm->window_size) {
+              D(("match offset beyond window boundaries"))
+              return qtm->error = MSPACK_ERR_DECRUNCH;
+            }
+            runsrc = &window[qtm->window_size - j];
+            if (j < i) {
+              /* if match goes over the window edge, do two copy runs */
+              i -= j; while (j-- > 0) *rundest++ = *runsrc++;
+              runsrc = window;
+            }
+            while (i-- > 0) *rundest++ = *runsrc++;
+          }
+          else {
+            runsrc = rundest - match_offset;
+            while (i-- > 0) *rundest++ = *runsrc++;
+          }
+          window_posn += match_length;
+        }
+      } /* if (window_posn+match_length > frame_end) */
+    } /* while (window_posn < frame_end) */
+
+    qtm->o_end = &window[window_posn];
+
+   /* if we subtracted too much from frame_todo, it will
+    * wrap around past zero and go above its max value */
+   if (frame_todo > QTM_FRAME_SIZE) {
+     D(("overshot frame alignment"))
+     return qtm->error = MSPACK_ERR_DECRUNCH;
+   }
+
+    /* another frame completed? */
+    if (frame_todo == 0) {
+      /* re-align input */
+      if (bits_left & 7) REMOVE_BITS(bits_left & 7);
+
+      /* special Quantum hack -- cabd.c injects a trailer byte to allow the
+       * decompressor to realign itself. CAB Quantum blocks, unlike LZX
+       * blocks, can have anything from 0 to 4 trailing null bytes. */
+      do { READ_BITS(i, 8); } while (i != 0xFF);
+
+      qtm->header_read = 0;
+
+      frame_todo = QTM_FRAME_SIZE;
+    }
+
+    /* window wrap? */
+    if (window_posn == qtm->window_size) {
+      /* flush all currently stored data */
+      i = (qtm->o_end - qtm->o_ptr);
+      /* break out if we have more than enough to finish this request */
+      if (i >= out_bytes) break;
+      if (qtm->sys->write(qtm->output, qtm->o_ptr, i) != i) {
+        return qtm->error = MSPACK_ERR_WRITE;
+      }
+      out_bytes -= i;
+      qtm->o_ptr = &window[0];
+      qtm->o_end = &window[0]; 
+      window_posn = 0;
+   }
+
+  } /* while (more bytes needed) */
+
+  if (out_bytes) {
+    i = (int) out_bytes;
+    if (qtm->sys->write(qtm->output, qtm->o_ptr, i) != i) {
+      return qtm->error = MSPACK_ERR_WRITE;
+    }
+    qtm->o_ptr += i;
+  }
+
+  /* store local state */
+
+  STORE_BITS;
+  qtm->window_posn = window_posn;
+  qtm->frame_todo = frame_todo;
+  qtm->H = H;
+  qtm->L = L;
+  qtm->C = C;
+
+  return MSPACK_ERR_OK;
+}
+
+void qtmd_free(struct qtmd_stream *qtm) {
+  struct mspack_system *sys;
+  if (qtm) {
+    sys = qtm->sys;
+    sys->free(qtm->window);
+    sys->free(qtm->inbuf);
+    sys->free(qtm);
+  }
+}