Merge branch 'john/erts/zlib-nif/OTP-14185' into maint

OTP-14527

1 files changed, 1019 insertions, 0 deletions

diff --git a/erts/emulator/nifs/common/zlib_nif.c b/erts/emulator/nifs/common/zlib_nif.c
new file mode 100644
index 0000000000..b7f3adaffe
--- /dev/null
+++ b/erts/emulator/nifs/common/zlib_nif.c
@@ -0,0 +1,1019 @@
+/*
+ * %CopyrightBegin%
+ *
+ * Copyright Ericsson 2017. All Rights Reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * %CopyrightEnd%
+ */
+
+#define STATIC_ERLANG_NIF 1
+
+#include <stdio.h>
+#include <zlib.h>
+
+#include "erl_nif.h"
+#include "config.h"
+#include "sys.h"
+
+#ifdef VALGRIND
+#  include <valgrind/memcheck.h>
+#endif
+
+#define INFL_DICT_SZ    (32768)
+
+#ifndef MAX
+#define MAX(X, Y) ((X) > (Y) ? (X) : (Y))
+#endif
+
+#ifndef MIN
+#define MIN(X, Y) ((X) < (Y) ? (X) : (Y))
+#endif
+
+/* NIF interface declarations */
+static int load(ErlNifEnv *env, void** priv_data, ERL_NIF_TERM load_info);
+static int upgrade(ErlNifEnv *env, void** priv_data, void** old_priv_data, ERL_NIF_TERM load_info);
+static void unload(ErlNifEnv *env, void* priv_data);
+
+static ErlNifResourceType *rtype_zlib;
+
+static ERL_NIF_TERM am_not_on_controlling_process;
+
+static ERL_NIF_TERM am_not_initialized;
+static ERL_NIF_TERM am_already_initialized;
+
+static ERL_NIF_TERM am_ok;
+static ERL_NIF_TERM am_error;
+
+static ERL_NIF_TERM am_continue;
+static ERL_NIF_TERM am_finished;
+
+static ERL_NIF_TERM am_not_supported;
+static ERL_NIF_TERM am_need_dictionary;
+
+static ERL_NIF_TERM am_empty;
+
+static ERL_NIF_TERM am_stream_end;
+static ERL_NIF_TERM am_stream_error;
+static ERL_NIF_TERM am_data_error;
+static ERL_NIF_TERM am_mem_error;
+static ERL_NIF_TERM am_buf_error;
+static ERL_NIF_TERM am_version_error;
+static ERL_NIF_TERM am_unknown_error;
+
+typedef enum {
+    ST_NONE    = 0,
+    ST_DEFLATE = 1,
+    ST_INFLATE = 2,
+    ST_CLOSED = 3
+} zlib_state;
+
+typedef struct {
+    z_stream s;
+    zlib_state state;
+
+    /* These refer to the plaintext CRC, and are only needed for zlib:crc32/1
+     * which is deprecated. */
+    uLong input_crc;
+    uLong output_crc;
+    int want_input_crc;
+    int want_output_crc;
+
+    int is_raw_stream;
+
+    int eos_seen;
+
+    /* DEPRECATED */
+    int inflateChunk_buffer_size;
+
+    ErlNifPid controlling_process;
+
+    ErlNifIOQueue *input_queue;
+
+    ErlNifEnv *stash_env;
+    ERL_NIF_TERM stash_term;
+} zlib_data_t;
+
+/* The NIFs: */
+
+static ERL_NIF_TERM zlib_open(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]);
+static ERL_NIF_TERM zlib_close(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]);
+static ERL_NIF_TERM zlib_deflateInit(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]);
+static ERL_NIF_TERM zlib_deflateInit2(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]);
+static ERL_NIF_TERM zlib_deflateSetDictionary(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]);
+static ERL_NIF_TERM zlib_deflateReset(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]);
+static ERL_NIF_TERM zlib_deflateEnd(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]);
+static ERL_NIF_TERM zlib_deflateParams(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]);
+static ERL_NIF_TERM zlib_deflate(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]);
+
+static ERL_NIF_TERM zlib_inflateInit(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]);
+static ERL_NIF_TERM zlib_inflateInit2(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]);
+static ERL_NIF_TERM zlib_inflateSetDictionary(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]);
+static ERL_NIF_TERM zlib_inflateGetDictionary(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]);
+static ERL_NIF_TERM zlib_inflateReset(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]);
+static ERL_NIF_TERM zlib_inflateEnd(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]);
+static ERL_NIF_TERM zlib_inflate(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]);
+
+static ERL_NIF_TERM zlib_crc32(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]);
+
+static ERL_NIF_TERM zlib_clearStash(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]);
+static ERL_NIF_TERM zlib_setStash(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]);
+static ERL_NIF_TERM zlib_getStash(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]);
+
+static ERL_NIF_TERM zlib_getBufSize(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]);
+static ERL_NIF_TERM zlib_setBufSize(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]);
+
+static ERL_NIF_TERM zlib_enqueue_input(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]);
+
+static ErlNifFunc nif_funcs[] = {
+    /* deflate */
+    {"deflateInit_nif", 2, zlib_deflateInit},
+    {"deflateInit_nif", 6, zlib_deflateInit2},
+    {"deflateSetDictionary_nif", 2, zlib_deflateSetDictionary},
+    {"deflateReset_nif", 1, zlib_deflateReset},
+    {"deflateEnd_nif", 1, zlib_deflateEnd},
+    {"deflateParams_nif", 3, zlib_deflateParams},
+    {"deflate_nif", 4, zlib_deflate},
+
+    /* inflate */
+    {"inflateInit_nif", 1, zlib_inflateInit},
+    {"inflateInit_nif", 2, zlib_inflateInit2},
+    {"inflateSetDictionary_nif", 2, zlib_inflateSetDictionary},
+    {"inflateGetDictionary_nif", 1, zlib_inflateGetDictionary},
+    {"inflateReset_nif", 1, zlib_inflateReset},
+    {"inflateEnd_nif", 1, zlib_inflateEnd},
+    {"inflate_nif", 4, zlib_inflate},
+
+    /* running checksum */
+    {"crc32_nif", 1, zlib_crc32},
+
+    /* open & close */
+    {"close_nif", 1, zlib_close},
+    {"open_nif", 0, zlib_open},
+
+    /* The stash keeps a single term alive across calls, and is used in
+     * exception_on_need_dict/1 to retain the old error behavior, and for
+     * saving data flushed through deflateParams/3. */
+    {"getStash_nif", 1, zlib_getStash},
+    {"clearStash_nif", 1, zlib_clearStash},
+    {"setStash_nif", 2, zlib_setStash},
+
+    /* DEPRECATED: buffer size for inflateChunk */
+    {"getBufSize_nif", 1, zlib_getBufSize},
+    {"setBufSize_nif", 2, zlib_setBufSize},
+
+    {"enqueue_nif", 2, zlib_enqueue_input},
+};
+
+ERL_NIF_INIT(zlib, nif_funcs, load, NULL, upgrade, unload)
+
+static void gc_zlib(ErlNifEnv *env, void* data);
+
+static int load(ErlNifEnv *env, void** priv_data, ERL_NIF_TERM load_info)
+{
+    am_not_on_controlling_process =
+        enif_make_atom(env, "not_on_controlling_process");
+
+    am_not_initialized = enif_make_atom(env, "not_initialized");
+    am_already_initialized = enif_make_atom(env, "already_initialized");
+
+    am_ok = enif_make_atom(env, "ok");
+    am_error = enif_make_atom(env, "error");
+
+    am_continue = enif_make_atom(env, "continue");
+    am_finished = enif_make_atom(env, "finished");
+
+    am_not_supported = enif_make_atom(env, "not_supported");
+    am_need_dictionary = enif_make_atom(env, "need_dictionary");
+
+    am_empty = enif_make_atom(env, "empty");
+
+    am_stream_end = enif_make_atom(env, "stream_end");
+    am_stream_error = enif_make_atom(env, "stream_error");
+    am_data_error = enif_make_atom(env, "data_error");
+    am_mem_error = enif_make_atom(env, "mem_error");
+    am_buf_error = enif_make_atom(env, "buf_error");
+    am_version_error = enif_make_atom(env, "version_error");
+    am_unknown_error = enif_make_atom(env, "unknown_error");
+
+    rtype_zlib = enif_open_resource_type(env, NULL,
+            "gc_zlib", gc_zlib, ERL_NIF_RT_CREATE, NULL);
+    *priv_data = NULL;
+
+    return 0;
+}
+
+static void unload(ErlNifEnv *env, void* priv_data)
+{
+
+}
+
+static int upgrade(ErlNifEnv *env, void** priv_data, void** old_priv_data, ERL_NIF_TERM load_info)
+{
+    if(*old_priv_data != NULL) {
+        return -1; /* Don't know how to do that */
+    }
+    if(*priv_data != NULL) {
+        return -1; /* Don't know how to do that */
+    }
+    if(load(env, priv_data, load_info)) {
+        return -1;
+    }
+    return 0;
+}
+
+static void* zlib_alloc(void* data, unsigned int items, unsigned int size)
+{
+    return (void*) enif_alloc(items * size);
+}
+
+static void zlib_free(void* data, void* addr)
+{
+    enif_free(addr);
+}
+
+static ERL_NIF_TERM zlib_return(ErlNifEnv *env, int code) {
+    ERL_NIF_TERM reason;
+    switch(code) {
+    case Z_OK:
+        reason = am_ok;
+        break;
+    case Z_STREAM_END:
+        reason = am_stream_end;
+        break;
+    case Z_ERRNO:
+        reason = enif_make_int(env, errno);
+        break;
+    case Z_STREAM_ERROR:
+        reason = enif_raise_exception(env, am_stream_error);
+        break;
+    case Z_DATA_ERROR:
+        reason = enif_raise_exception(env, am_data_error);
+        break;
+    case Z_MEM_ERROR:
+        reason = am_mem_error;
+        break;
+    case Z_BUF_ERROR:
+        reason = am_buf_error;
+        break;
+    case Z_VERSION_ERROR:
+        reason = am_version_error;
+        break;
+    default:
+        reason = am_unknown_error;
+        break;
+    }
+    return reason;
+}
+
+static void gc_zlib(ErlNifEnv *env, void* data) {
+    zlib_data_t *d = (zlib_data_t*)data;
+
+    if(d->state == ST_DEFLATE) {
+        deflateEnd(&d->s);
+    } else if(d->state == ST_INFLATE) {
+        inflateEnd(&d->s);
+    }
+
+    if(d->state != ST_CLOSED) {
+        enif_ioq_destroy(d->input_queue);
+
+        if(d->stash_env != NULL) {
+            enif_free_env(d->stash_env);
+        }
+
+        d->state = ST_CLOSED;
+    }
+}
+
+static int get_zlib_data(ErlNifEnv *env, ERL_NIF_TERM opaque, zlib_data_t **d) {
+    return enif_get_resource(env, opaque, rtype_zlib, (void **)d);
+}
+
+static int zlib_process_check(ErlNifEnv *env, zlib_data_t *d) {
+    ErlNifPid current_process;
+
+    enif_self(env, &current_process);
+
+    return enif_is_identical(enif_make_pid(env, &current_process),
+        enif_make_pid(env, &d->controlling_process));
+}
+
+static void zlib_reset_input(zlib_data_t *d) {
+    enif_ioq_destroy(d->input_queue);
+    d->input_queue = enif_ioq_create(ERL_NIF_IOQ_NORMAL);
+
+    if(d->stash_env != NULL) {
+        enif_free_env(d->stash_env);
+        d->stash_env = NULL;
+        d->stash_term = NIL;
+    }
+}
+
+static int zlib_flush_queue(int (*codec)(z_stream*, int), ErlNifEnv *env,
+        zlib_data_t *d, size_t input_limit, ErlNifBinary *output_buffer, int flush,
+        size_t *bytes_produced, size_t *bytes_consumed, size_t *bytes_remaining) {
+
+    int vec_len, vec_idx;
+    SysIOVec *input_vec;
+    int res;
+
+    input_vec = enif_ioq_peek(d->input_queue, &vec_len);
+    vec_idx = 0;
+    res = Z_OK;
+
+    *bytes_produced = 0;
+    *bytes_consumed = 0;
+
+    d->s.avail_out = output_buffer->size;
+    d->s.next_out = output_buffer->data;
+
+    while(res == Z_OK && vec_idx < vec_len && *bytes_consumed < input_limit) {
+        size_t timeslice_percent, block_consumed, block_size;
+
+        block_size = MIN(input_vec[vec_idx].iov_len, input_limit);
+
+        d->s.next_in = input_vec[vec_idx].iov_base;
+        d->s.avail_in = block_size;
+
+        res = codec(&d->s, Z_NO_FLUSH);
+
+        ASSERT(d->s.avail_in == 0 || d->s.avail_out == 0 || res != Z_OK);
+
+        block_consumed = block_size - d->s.avail_in;
+        *bytes_consumed += block_consumed;
+
+        if(d->want_input_crc) {
+            d->input_crc =
+                crc32(d->input_crc, input_vec[vec_idx].iov_base, block_consumed);
+        }
+
+        timeslice_percent = (100 * block_consumed) / input_limit;
+        if(enif_consume_timeslice(env, MAX(1, timeslice_percent))) {
+            break;
+        }
+
+        vec_idx++;
+    }
+
+    if(!enif_ioq_deq(d->input_queue, *bytes_consumed, bytes_remaining)) {
+        *bytes_remaining = 0;
+        res = Z_BUF_ERROR;
+    }
+
+    if(res == Z_OK && flush != Z_NO_FLUSH && (*bytes_remaining == 0)) {
+        d->s.next_in = NULL;
+        d->s.avail_in = 0;
+
+        res = codec(&d->s, flush);
+    }
+
+    *bytes_produced = output_buffer->size - d->s.avail_out;
+
+    return res;
+}
+
+static ERL_NIF_TERM zlib_codec(int (*codec)(z_stream*, int),
+                               ErlNifEnv *env, zlib_data_t *d,
+                               int input_chunk_size,
+                               int output_chunk_size,
+                               int flush) {
+
+    size_t bytes_produced, bytes_consumed, bytes_remaining;
+    ErlNifBinary output_buffer;
+    int res;
+
+    if(!enif_alloc_binary(output_chunk_size, &output_buffer)) {
+        return zlib_return(env, Z_MEM_ERROR);
+    }
+
+    res = zlib_flush_queue(codec, env, d, input_chunk_size, &output_buffer,
+        flush, &bytes_produced, &bytes_consumed, &bytes_remaining);
+
+    if(res < 0 && res != Z_BUF_ERROR) {
+        enif_release_binary(&output_buffer);
+        return zlib_return(env, res);
+    }
+
+    if(res == Z_STREAM_END) {
+        d->eos_seen = 1;
+    }
+
+    if(d->want_output_crc) {
+        d->output_crc =
+            crc32(d->output_crc, output_buffer.data, bytes_produced);
+    }
+
+    if(bytes_consumed == 0 && bytes_produced == 0 && bytes_remaining != 0) {
+        /* Die if we've made zero progress; this should not happen on
+         * well-formed input. */
+
+        enif_release_binary(&output_buffer);
+        return zlib_return(env, Z_DATA_ERROR);
+    } else {
+        ERL_NIF_TERM flushed_output;
+
+        if(bytes_produced > 0) {
+            if(bytes_produced < output_buffer.size) {
+                enif_realloc_binary(&output_buffer, bytes_produced);
+            }
+
+            flushed_output =
+                enif_make_list1(env, enif_make_binary(env, &output_buffer));
+        } else {
+            enif_release_binary(&output_buffer);
+            flushed_output = enif_make_list(env, 0);
+        }
+
+        if(bytes_remaining == 0 && bytes_produced < output_chunk_size) {
+            return enif_make_tuple2(env, am_finished, flushed_output);
+        } else if(res != Z_NEED_DICT) {
+            return enif_make_tuple2(env, am_continue, flushed_output);
+        }
+
+        return enif_make_tuple3(env, am_need_dictionary,
+            enif_make_int(env, d->s.adler), flushed_output);
+    }
+}
+
+/* zlib nifs */
+
+static ERL_NIF_TERM zlib_getStash(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]) {
+    zlib_data_t *d;
+
+    if(argc != 1 || !get_zlib_data(env, argv[0], &d)) {
+        return enif_make_badarg(env);
+    } else if(!zlib_process_check(env, d)) {
+        return enif_raise_exception(env, am_not_on_controlling_process);
+    }
+
+    if(d->stash_env == NULL) {
+        return am_empty;
+    }
+
+    return enif_make_tuple2(env, am_ok, enif_make_copy(env, d->stash_term));
+}
+
+static ERL_NIF_TERM zlib_clearStash(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]) {
+    zlib_data_t *d;
+
+    if(argc != 1 || !get_zlib_data(env, argv[0], &d)) {
+        return enif_make_badarg(env);
+    } else if(!zlib_process_check(env, d)) {
+        return enif_raise_exception(env, am_not_on_controlling_process);
+    } else if(d->stash_env == NULL) {
+        return enif_raise_exception(env, am_error);
+    }
+
+    enif_free_env(d->stash_env);
+    d->stash_env = NULL;
+    d->stash_term = NIL;
+
+    return am_ok;
+}
+
+static ERL_NIF_TERM zlib_setStash(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]) {
+    zlib_data_t *d;
+
+    if(argc != 2 || !get_zlib_data(env, argv[0], &d)) {
+        return enif_make_badarg(env);
+    } else if(!zlib_process_check(env, d)) {
+        return enif_raise_exception(env, am_not_on_controlling_process);
+    } else if(d->stash_env != NULL) {
+        return enif_raise_exception(env, am_error);
+    }
+
+    d->stash_env = enif_alloc_env();
+    d->stash_term = enif_make_copy(d->stash_env, argv[1]);
+
+    return am_ok;
+}
+
+static ERL_NIF_TERM zlib_open(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]) {
+    zlib_data_t *d;
+    ERL_NIF_TERM result;
+
+    d = (zlib_data_t *) enif_alloc_resource(rtype_zlib, sizeof(zlib_data_t));
+
+    memset(&d->s, 0, sizeof(z_stream));
+
+    enif_self(env, &d->controlling_process);
+
+    d->input_queue = enif_ioq_create(ERL_NIF_IOQ_NORMAL);
+
+    d->s.zalloc = zlib_alloc;
+    d->s.zfree  = zlib_free;
+    d->s.opaque = d;
+    d->s.data_type = Z_BINARY;
+
+    d->state = ST_NONE;
+    d->eos_seen = 0;
+
+    d->want_output_crc = 0;
+    d->want_input_crc = 0;
+    d->is_raw_stream = 0;
+
+    d->output_crc = crc32(0L, Z_NULL, 0);
+    d->input_crc = crc32(0L, Z_NULL, 0);
+
+    d->stash_env = NULL;
+    d->stash_term = NIL;
+
+    d->inflateChunk_buffer_size = 4000;
+
+    result = enif_make_resource(env, d);
+    enif_release_resource(d);
+
+    return result;
+}
+
+static ERL_NIF_TERM zlib_close(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]) {
+    zlib_data_t *d;
+
+    /* strictly speaking not needed since the gc will handle this */
+    if(argc != 1 || !get_zlib_data(env, argv[0], &d)) {
+        return enif_make_badarg(env);
+    } else if(!zlib_process_check(env, d)) {
+        return enif_raise_exception(env, am_not_on_controlling_process);
+    } else if(d->state == ST_CLOSED) {
+        return enif_raise_exception(env, am_not_initialized);
+    }
+
+    gc_zlib(env, d);
+
+    return am_ok;
+}
+
+/* deflate */
+
+static ERL_NIF_TERM zlib_deflateInit(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]) {
+    zlib_data_t *d;
+    int level, res;
+
+    if(argc != 2 || !get_zlib_data(env, argv[0], &d) ||
+                    !enif_get_int(env, argv[1], &level)) {
+        return enif_make_badarg(env);
+    } else if(!zlib_process_check(env, d)) {
+        return enif_raise_exception(env, am_not_on_controlling_process);
+    } else if(d->state != ST_NONE) {
+        return enif_raise_exception(env, am_already_initialized);
+    }
+
+    res = deflateInit(&d->s, level);
+
+    if(res == Z_OK) {
+        d->state = ST_DEFLATE;
+        d->eos_seen = 0;
+
+        /* FIXME: crc32/1 is documented as returning "the current calculated
+         * checksum," but failed to mention that the old implementation only
+         * calculated it when WindowBits < 0 (See zlib_deflateInit2).
+         *
+         * We could fix this behavior by setting d->want_input_crc to 1 here,
+         * but we've decided to retain this quirk since the performance hit is
+         * quite significant. */
+        d->want_output_crc = 0;
+        d->want_input_crc = 0;
+
+        d->output_crc = crc32(0L, Z_NULL, 0);
+        d->input_crc = crc32(0L, Z_NULL, 0);
+    }
+
+    return zlib_return(env, res);
+}
+
+static ERL_NIF_TERM zlib_deflateInit2(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]) {
+    zlib_data_t *d;
+    int level, method, windowBits, memLevel, strategy, res;
+
+    if(argc != 6 || !get_zlib_data(env, argv[0], &d) 
+                 || !enif_get_int(env, argv[1], &level)
+                 || !enif_get_int(env, argv[2], &method)
+                 || !enif_get_int(env, argv[3], &windowBits)
+                 || !enif_get_int(env, argv[4], &memLevel)
+                 || !enif_get_int(env, argv[5], &strategy)) {
+        return enif_make_badarg(env);
+    } else if(!zlib_process_check(env, d)) {
+        return enif_raise_exception(env, am_not_on_controlling_process);
+    } else if(d->state != ST_NONE) {
+        return enif_raise_exception(env, am_already_initialized);
+    }
+
+    res = deflateInit2(&d->s, level, method, windowBits, memLevel, strategy);
+
+    if(res == Z_OK) {
+        d->state = ST_DEFLATE;
+        d->eos_seen = 0;
+
+        d->is_raw_stream = (windowBits < 0);
+
+        d->want_output_crc = 0;
+        d->want_input_crc = d->is_raw_stream;
+
+        d->output_crc = crc32(0L, Z_NULL, 0);
+        d->input_crc = crc32(0L, Z_NULL, 0);
+    }
+
+    return zlib_return(env, res);
+}
+
+static ERL_NIF_TERM zlib_deflateSetDictionary(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]) {
+    zlib_data_t *d;
+    ErlNifBinary bin;
+    int res;
+
+    if(argc != 2 || !get_zlib_data(env, argv[0], &d)
+                 || !enif_inspect_iolist_as_binary(env, argv[1], &bin)) {
+        return enif_make_badarg(env);
+    } else if(!zlib_process_check(env, d)) {
+        return enif_raise_exception(env, am_not_on_controlling_process);
+    } else if(d->state != ST_DEFLATE) {
+        return enif_raise_exception(env, am_not_initialized);
+    }
+
+    if((res = deflateSetDictionary(&d->s, bin.data, bin.size)) == Z_OK) {
+        uLong checksum = d->s.adler;
+
+        /* d->s.adler is not updated in raw deflate mode, so we'll calculate it
+         * ourselves in case the user wants to rely on that behavior. */
+        if(d->is_raw_stream) {
+            checksum = adler32(0, bin.data, bin.size);
+        }
+
+        return enif_make_int(env, checksum);
+    }
+
+    return zlib_return(env, res);
+}
+
+static ERL_NIF_TERM zlib_deflateReset(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]) {
+    zlib_data_t *d;
+    int res;
+
+    if(argc != 1 || !get_zlib_data(env, argv[0], &d)) {
+        return enif_make_badarg(env);
+    } else if(!zlib_process_check(env, d)) {
+        return enif_raise_exception(env, am_not_on_controlling_process);
+    } else if(d->state != ST_DEFLATE) {
+        return enif_raise_exception(env, am_not_initialized);
+    }
+
+    res = deflateReset(&d->s);
+
+    d->input_crc = crc32(0L, Z_NULL, 0);
+    d->eos_seen = 0;
+
+    zlib_reset_input(d);
+
+    return zlib_return(env, res);
+}
+
+static ERL_NIF_TERM zlib_deflateEnd(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]) {
+    zlib_data_t *d;
+    int res;
+
+    if(argc != 1 || !get_zlib_data(env, argv[0], &d)) {
+        return enif_make_badarg(env);
+    } else if(!zlib_process_check(env, d)) {
+        return enif_raise_exception(env, am_not_on_controlling_process);
+    } else if(d->state != ST_DEFLATE) {
+        return enif_raise_exception(env, am_not_initialized);
+    }
+
+    res = deflateEnd(&d->s);
+
+    if(res == Z_OK && enif_ioq_size(d->input_queue) > 0) {
+        res = Z_DATA_ERROR;
+    }
+
+    zlib_reset_input(d);
+    d->state = ST_NONE;
+
+    return zlib_return(env, res);
+}
+
+static ERL_NIF_TERM zlib_deflateParams(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]) {
+    zlib_data_t *d;
+    int res, level, strategy;
+
+    if(argc != 3 || !get_zlib_data(env, argv[0], &d)
+                 || !enif_get_int(env, argv[1], &level)
+                 || !enif_get_int(env, argv[2], &strategy)) {
+        return enif_make_badarg(env);
+    } else if(!zlib_process_check(env, d)) {
+        return enif_raise_exception(env, am_not_on_controlling_process);
+    } else if(d->state != ST_DEFLATE) {
+        return enif_raise_exception(env, am_not_initialized);
+    }
+
+    /* deflateParams will flush everything currently in the stream, corrupting
+     * the heap unless it's empty. We therefore pretend to have a full output
+     * buffer, forcing a Z_BUF_ERROR if there's anything left to be flushed. */
+    d->s.avail_out = 0;
+    res = deflateParams(&d->s, level, strategy);
+
+    return zlib_return(env, res);
+}
+
+static ERL_NIF_TERM zlib_deflate(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]) {
+    zlib_data_t *d;
+
+    int input_chunk_size, output_chunk_size, flush;
+
+    if(argc != 4 || !get_zlib_data(env, argv[0], &d)
+                 || !enif_get_int(env, argv[1], &input_chunk_size)
+                 || !enif_get_int(env, argv[2], &output_chunk_size)
+                 || !enif_get_int(env, argv[3], &flush)) {
+        return enif_make_badarg(env);
+    } else if(!zlib_process_check(env, d)) {
+        return enif_raise_exception(env, am_not_on_controlling_process);
+    } else if(d->state != ST_DEFLATE) {
+        return enif_raise_exception(env, am_not_initialized);
+    }
+
+    return zlib_codec(&deflate, env, d, input_chunk_size, output_chunk_size, flush);
+}
+
+/* inflate */
+
+static ERL_NIF_TERM zlib_inflateInit(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]) {
+    zlib_data_t *d;
+    int res;
+
+    if(argc != 1 || !get_zlib_data(env, argv[0], &d)) {
+        return enif_make_badarg(env);
+    } else if(!zlib_process_check(env, d)) {
+        return enif_raise_exception(env, am_not_on_controlling_process);
+    } else if(d->state != ST_NONE) {
+        return enif_raise_exception(env, am_already_initialized);
+    }
+
+    res = inflateInit(&d->s);
+
+    if(res == Z_OK) {
+        d->state = ST_INFLATE;
+        d->eos_seen = 0;
+
+        d->want_output_crc = 0;
+        d->want_input_crc = 0;
+        d->is_raw_stream = 0;
+
+        d->output_crc = crc32(0L, Z_NULL, 0);
+        d->input_crc = crc32(0L, Z_NULL, 0);
+    }
+
+    return zlib_return(env, res);
+}
+
+static ERL_NIF_TERM zlib_inflateInit2(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]) {
+    zlib_data_t *d;
+    int windowBits, res;
+
+    if(argc != 2 || !get_zlib_data(env, argv[0], &d)
+                 || !enif_get_int(env, argv[1], &windowBits)) {
+        return enif_make_badarg(env);
+    } else if(!zlib_process_check(env, d)) {
+        return enif_raise_exception(env, am_not_on_controlling_process);
+    } else if(d->state != ST_NONE) {
+        return enif_raise_exception(env, am_already_initialized);
+    }
+
+    res = inflateInit2(&d->s, windowBits);
+
+    if(res == Z_OK) {
+        d->state = ST_INFLATE;
+        d->eos_seen = 0;
+
+        d->is_raw_stream = (windowBits < 0);
+
+        d->want_output_crc = d->is_raw_stream;
+        d->want_input_crc = 0;
+
+        d->output_crc = crc32(0L, Z_NULL, 0);
+        d->input_crc = crc32(0L, Z_NULL, 0);
+    }
+
+    return zlib_return(env, res);
+}
+
+static ERL_NIF_TERM zlib_inflateSetDictionary(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]) {
+    zlib_data_t *d;
+    ErlNifBinary bin;
+    int res;
+
+    if(argc != 2 || !get_zlib_data(env, argv[0], &d)
+                 || !enif_inspect_iolist_as_binary(env, argv[1], &bin)) {
+        return enif_make_badarg(env);
+    } else if(!zlib_process_check(env, d)) {
+        return enif_raise_exception(env, am_not_on_controlling_process);
+    } else if(d->state != ST_INFLATE) {
+        return enif_raise_exception(env, am_not_initialized);
+    }
+
+    res = inflateSetDictionary(&d->s, bin.data, bin.size);
+
+    return zlib_return(env, res);
+}
+
+#ifdef HAVE_ZLIB_INFLATEGETDICTIONARY
+/* Work around broken build system with runtime version test */
+static int zlib_supports_inflateGetDictionary(void) {
+    static int supportsGetDictionary = -1;
+
+#if defined(__APPLE__) && defined(__MACH__)
+    if(supportsGetDictionary < 0) {
+        unsigned int v[4] = {0, 0, 0, 0};
+        unsigned hexver;
+
+        sscanf(zlibVersion(), "%u.%u.%u.%u", &v[0], &v[1], &v[2], &v[3]);
+
+        hexver = (v[0] << (8*3)) | (v[1] << (8*2)) | (v[2] << (8)) | v[3];
+        supportsGetDictionary = (hexver >= 0x1020701); /* 1.2.7.1 */
+    }
+#endif
+
+    return supportsGetDictionary;
+}
+#endif
+
+static ERL_NIF_TERM zlib_inflateGetDictionary(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]) {
+    zlib_data_t *d;
+
+    if(argc != 1 || !get_zlib_data(env, argv[0], &d)) {
+        return enif_make_badarg(env);
+    } else if(!zlib_process_check(env, d)) {
+        return enif_raise_exception(env, am_not_on_controlling_process);
+    } else if(d->state != ST_INFLATE) {
+        return enif_raise_exception(env, am_not_initialized);
+    }
+
+#ifdef HAVE_ZLIB_INFLATEGETDICTIONARY
+    if(zlib_supports_inflateGetDictionary()) {
+        ErlNifBinary obin;
+        uInt len;
+        int res;
+
+        enif_alloc_binary(INFL_DICT_SZ, &obin);
+        len = 0;
+
+        if((res = inflateGetDictionary(&d->s, obin.data, &len)) < 0) {
+            enif_release_binary(&obin);
+            return zlib_return(env, res);
+        }
+
+        enif_realloc_binary(&obin, (size_t)len);
+        return enif_make_binary(env, &obin);
+    }
+#endif
+
+    return enif_raise_exception(env, am_not_supported);
+}
+
+static ERL_NIF_TERM zlib_inflateReset(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]) {
+    zlib_data_t *d;
+    int res;
+
+    if(argc != 1 || !get_zlib_data(env, argv[0], &d)) {
+        return enif_make_badarg(env);
+    } else if(!zlib_process_check(env, d)) {
+        return enif_raise_exception(env, am_not_on_controlling_process);
+    } else if(d->state != ST_INFLATE) {
+        return enif_raise_exception(env, am_not_initialized);
+    }
+
+    res = inflateReset(&d->s);
+
+    d->output_crc = crc32(0L, Z_NULL, 0);
+    d->eos_seen = 0;
+
+    zlib_reset_input(d);
+
+    return zlib_return(env, res);
+}
+
+static ERL_NIF_TERM zlib_inflateEnd(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]) {
+    zlib_data_t *d;
+    int res;
+
+    if(argc != 1 || !get_zlib_data(env, argv[0], &d)) {
+        return enif_make_badarg(env);
+    } else if(!zlib_process_check(env, d)) {
+        return enif_raise_exception(env, am_not_on_controlling_process);
+    } else if(d->state != ST_INFLATE) {
+        return enif_raise_exception(env, am_not_initialized);
+    }
+
+    res = inflateEnd(&d->s);
+
+    if(res == Z_OK && (!d->eos_seen || enif_ioq_size(d->input_queue) > 0)) {
+        res = Z_DATA_ERROR;
+    }
+
+    zlib_reset_input(d);
+    d->state = ST_NONE;
+
+    return zlib_return(env, res);
+}
+
+static ERL_NIF_TERM zlib_inflate(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]) {
+    zlib_data_t *d;
+
+    int input_chunk_size, output_chunk_size, flush;
+
+    if(argc != 4 || !get_zlib_data(env, argv[0], &d)
+                 || !enif_get_int(env, argv[1], &input_chunk_size)
+                 || !enif_get_int(env, argv[2], &output_chunk_size)
+                 || !enif_get_int(env, argv[3], &flush)) {
+        return enif_make_badarg(env);
+    } else if(!zlib_process_check(env, d)) {
+        return enif_raise_exception(env, am_not_on_controlling_process);
+    } else if(d->state != ST_INFLATE) {
+        return enif_raise_exception(env, am_not_initialized);
+    }
+
+    return zlib_codec(&inflate, env, d, input_chunk_size, output_chunk_size, flush);
+}
+
+static ERL_NIF_TERM zlib_crc32(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]) {
+    zlib_data_t *d;
+
+    if(argc != 1 || !get_zlib_data(env, argv[0], &d)) {
+        return enif_make_badarg(env);
+    } else if(!zlib_process_check(env, d)) {
+        return enif_raise_exception(env, am_not_on_controlling_process);
+    }
+
+    if(d->state == ST_DEFLATE) {
+        return enif_make_ulong(env, d->input_crc);
+    } else if(d->state == ST_INFLATE) {
+        return enif_make_ulong(env, d->output_crc);
+    }
+
+    return enif_raise_exception(env, am_not_initialized);
+}
+
+static ERL_NIF_TERM zlib_getBufSize(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]) {
+    zlib_data_t *d;
+
+    if(argc != 1 || !get_zlib_data(env, argv[0], &d)) {
+        return enif_make_badarg(env);
+    } else if(!zlib_process_check(env, d)) {
+        return enif_raise_exception(env, am_not_on_controlling_process);
+    }
+
+    return enif_make_int(env, d->inflateChunk_buffer_size);
+}
+
+static ERL_NIF_TERM zlib_setBufSize(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]) {
+    zlib_data_t *d;
+
+    if(argc != 2 || !get_zlib_data(env, argv[0], &d)) {
+        return enif_make_badarg(env);
+    } else if(!zlib_process_check(env, d)) {
+        return enif_raise_exception(env, am_not_on_controlling_process);
+    }
+
+    if(!enif_get_int(env, argv[1], &d->inflateChunk_buffer_size)) {
+        return enif_make_badarg(env);
+    }
+
+    return am_ok;
+}
+
+static ERL_NIF_TERM zlib_enqueue_input(ErlNifEnv *env, int argc, const ERL_NIF_TERM argv[]) {
+    zlib_data_t *d;
+
+    ErlNifIOVec prealloc, *iovec = &prealloc;
+    ERL_NIF_TERM tail;
+
+    if(argc != 2 || !get_zlib_data(env, argv[0], &d)) {
+        return enif_make_badarg(env);
+    } else if(!zlib_process_check(env, d)) {
+        return enif_raise_exception(env, am_not_on_controlling_process);
+    } else if(d->state != ST_DEFLATE && d->state != ST_INFLATE) {
+        return enif_raise_exception(env, am_not_initialized);
+    }
+
+    if(!enif_inspect_iovec(env, 256, argv[1], &tail, &iovec)) {
+        return enif_make_badarg(env);
+    } else if(!enif_ioq_enqv(d->input_queue, iovec, 0)) {
+        return enif_make_badarg(env);
+    }
+
+    if(!enif_is_empty_list(env, tail)) {
+        return enif_make_tuple2(env, am_continue, tail);
+    }
+
+    return am_ok;
+}