Zlib ng

2026-05-31 13:16:39 +00:00 · 2019-06-30 18:13:46 -07:00
parent d7c110041a
commit e086f53b97
116 changed files with 30587 additions and 13 deletions
@@ -0,0 +1,142 @@
+/* dfltcc_inflate.c - IBM Z DEFLATE CONVERSION CALL decompression support. */
+
+/*
+   Use the following commands to build zlib-ng with DFLTCC decompression support:
+
+        $ ./configure --with-dfltcc-inflate
+   or
+
+        $ cmake -DWITH_DFLTCC_INFLATE=1 .
+
+   and then
+
+        $ make
+*/
+
+#include "zbuild.h"
+#include "zutil.h"
+#include "inftrees.h"
+#include "inflate.h"
+#include "dfltcc_inflate.h"
+#include "dfltcc_detail.h"
+
+int ZLIB_INTERNAL dfltcc_can_inflate(PREFIX3(streamp) strm)
+{
+    struct inflate_state *state = (struct inflate_state *)strm->state;
+    struct dfltcc_state *dfltcc_state = GET_DFLTCC_STATE(state);
+
+    /* Unsupported compression settings */
+    if (state->wbits != HB_BITS)
+        return 0;
+
+    /* Unsupported hardware */
+    return is_bit_set(dfltcc_state->af.fns, DFLTCC_XPND) && is_bit_set(dfltcc_state->af.fmts, DFLTCC_FMT0);
+}
+
+static inline dfltcc_cc dfltcc_xpnd(PREFIX3(streamp) strm)
+{
+    struct inflate_state *state = (struct inflate_state *)strm->state;
+    struct dfltcc_param_v0 *param = &GET_DFLTCC_STATE(state)->param;
+    size_t avail_in = strm->avail_in;
+    size_t avail_out = strm->avail_out;
+    dfltcc_cc cc;
+
+    cc = dfltcc(DFLTCC_XPND | HBT_CIRCULAR,
+                param, &strm->next_out, &avail_out,
+                &strm->next_in, &avail_in, state->window);
+    strm->avail_in = avail_in;
+    strm->avail_out = avail_out;
+    return cc;
+}
+
+dfltcc_inflate_action ZLIB_INTERNAL dfltcc_inflate(PREFIX3(streamp) strm, int flush, int *ret)
+{
+    struct inflate_state *state = (struct inflate_state *)strm->state;
+    struct dfltcc_state *dfltcc_state = GET_DFLTCC_STATE(state);
+    struct dfltcc_param_v0 *param = &dfltcc_state->param;
+    dfltcc_cc cc;
+
+    if (flush == Z_BLOCK || flush == Z_TREES) {
+        /* DFLTCC does not support stopping on block boundaries */
+        if (dfltcc_inflate_disable(strm)) {
+            *ret = Z_STREAM_ERROR;
+            return DFLTCC_INFLATE_BREAK;
+        } else
+            return DFLTCC_INFLATE_SOFTWARE;
+    }
+
+    if (state->last) {
+        if (state->bits != 0) {
+            strm->next_in++;
+            strm->avail_in--;
+            state->bits = 0;
+        }
+        state->mode = CHECK;
+        return DFLTCC_INFLATE_CONTINUE;
+    }
+
+    if (strm->avail_in == 0 && !param->cf)
+        return DFLTCC_INFLATE_BREAK;
+
+    if (inflate_ensure_window(state)) {
+        state->mode = MEM;
+        return DFLTCC_INFLATE_CONTINUE;
+    }
+
+    /* Translate stream to parameter block */
+    param->cvt = state->flags ? CVT_CRC32 : CVT_ADLER32;
+    param->sbb = state->bits;
+    param->hl = state->whave; /* Software and hardware history formats match */
+    param->ho = (state->wnext - state->whave) & ((1 << HB_BITS) - 1);
+    if (param->hl)
+        param->nt = 0; /* Honor history for the first block */
+    param->cv = state->flags ? ZSWAP32(state->check) : state->check;
+
+    /* Inflate */
+    do {
+        cc = dfltcc_xpnd(strm);
+    } while (cc == DFLTCC_CC_AGAIN);
+
+    /* Translate parameter block to stream */
+    strm->msg = oesc_msg(dfltcc_state->msg, param->oesc);
+    state->last = cc == DFLTCC_CC_OK;
+    state->bits = param->sbb;
+    state->whave = param->hl;
+    state->wnext = (param->ho + param->hl) & ((1 << HB_BITS) - 1);
+    state->check = state->flags ? ZSWAP32(param->cv) : param->cv;
+    if (cc == DFLTCC_CC_OP2_CORRUPT && param->oesc != 0) {
+        /* Report an error if stream is corrupted */
+        state->mode = BAD;
+        return DFLTCC_INFLATE_CONTINUE;
+    }
+    state->mode = TYPEDO;
+    /* Break if operands are exhausted, otherwise continue looping */
+    return (cc == DFLTCC_CC_OP1_TOO_SHORT || cc == DFLTCC_CC_OP2_TOO_SHORT) ?
+        DFLTCC_INFLATE_BREAK : DFLTCC_INFLATE_CONTINUE;
+}
+
+int ZLIB_INTERNAL dfltcc_was_inflate_used(PREFIX3(streamp) strm)
+{
+    struct inflate_state *state = (struct inflate_state *)strm->state;
+    struct dfltcc_param_v0 *param = &GET_DFLTCC_STATE(state)->param;
+
+    return !param->nt;
+}
+
+int ZLIB_INTERNAL dfltcc_inflate_disable(PREFIX3(streamp) strm)
+{
+    struct inflate_state *state = (struct inflate_state *)strm->state;
+    struct dfltcc_state *dfltcc_state = GET_DFLTCC_STATE(state);
+
+    if (!dfltcc_can_inflate(strm))
+        return 0;
+    if (dfltcc_was_inflate_used(strm))
+        /* DFLTCC has already decompressed some data. Since there is not
+         * enough information to resume decompression in software, the call
+         * must fail.
+         */
+        return 1;
+    /* DFLTCC was not used yet - decompress in software */
+    memset(&dfltcc_state->af, 0, sizeof(dfltcc_state->af));
+    return 0;
+}