Add wimlib_get_compressor_needed_memory()

[wimlib] / src / lzms-compress.c

diff --git a/src/lzms-compress.c b/src/lzms-compress.c
index 31648f0aee6b4f12ae59ee9f53d556fb41d5e800..72aef31b14fda69dd530bb7c5bc8e1cfaeccd92b 100644 (file)
--- a/src/lzms-compress.c
+++ b/src/lzms-compress.c
@@ -1226,7 +1226,7 @@ lzms_free_compressor(void *_ctx)
        }
 }
 
-static const struct wimlib_lzms_compressor_params default_params = {
+static const struct wimlib_lzms_compressor_params lzms_default = {
        .hdr = sizeof(struct wimlib_lzms_compressor_params),
        .min_match_length = 2,
        .max_match_length = UINT32_MAX,
@@ -1236,37 +1236,36 @@ static const struct wimlib_lzms_compressor_params default_params = {
        .optim_array_length = 1024,
 };
 
+static const struct wimlib_lzms_compressor_params *
+lzms_get_params(const struct wimlib_compressor_params_header *_params)
+{
+       const struct wimlib_lzms_compressor_params *params =
+               (const struct wimlib_lzms_compressor_params*)_params;
+
+       if (params == NULL)
+               params = &lzms_default;
+
+       return params;
+}
+
 static int
 lzms_create_compressor(size_t max_block_size,
                       const struct wimlib_compressor_params_header *_params,
                       void **ctx_ret)
 {
        struct lzms_compressor *ctx;
-       const struct wimlib_lzms_compressor_params *params;
+       const struct wimlib_lzms_compressor_params *params = lzms_get_params(_params);
 
        if (max_block_size == 0 || max_block_size >= INT32_MAX) {
                LZMS_DEBUG("Invalid max_block_size (%u)", max_block_size);
                return WIMLIB_ERR_INVALID_PARAM;
        }
 
-       if (_params)
-               params = (const struct wimlib_lzms_compressor_params*)_params;
-       else
-               params = &default_params;
-
-       if (params->max_match_length < params->min_match_length ||
-           params->min_match_length < 2 ||
-           params->optim_array_length == 0 ||
-           min(params->max_match_length, params->nice_match_length) > 65536) {
-               LZMS_DEBUG("Invalid compression parameter!");
-               return WIMLIB_ERR_INVALID_PARAM;
-       }
-
        ctx = CALLOC(1, sizeof(struct lzms_compressor));
        if (ctx == NULL)
                goto oom;
 
-       ctx->window = MALLOC(max_block_size + 8);
+       ctx->window = MALLOC(max_block_size);
        if (ctx->window == NULL)
                goto oom;
 
@@ -1312,7 +1311,46 @@ oom:
        return WIMLIB_ERR_NOMEM;
 }
 
+static u64
+lzms_get_needed_memory(size_t max_block_size,
+                      const struct wimlib_compressor_params_header *_params)
+{
+       const struct wimlib_lzms_compressor_params *params = lzms_get_params(_params);
+
+       u64 size = 0;
+
+       size += max_block_size;
+       size += sizeof(struct lzms_compressor);
+       size += lz_sarray_get_needed_memory(max_block_size);
+       size += lz_match_chooser_get_needed_memory(params->optim_array_length,
+                                                  params->nice_match_length,
+                                                  params->max_match_length);
+       size += min(params->max_match_length -
+                   params->min_match_length + 1,
+                   params->max_matches_per_pos) *
+               sizeof(((struct lzms_compressor*)0)->matches[0]);
+       return size;
+}
+
+static bool
+lzms_params_valid(const struct wimlib_compressor_params_header *_params)
+{
+       const struct wimlib_lzms_compressor_params *params =
+               (const struct wimlib_lzms_compressor_params*)_params;
+
+       if (params->hdr.size != sizeof(*params) ||
+           params->max_match_length < params->min_match_length ||
+           params->min_match_length < 2 ||
+           params->optim_array_length == 0 ||
+           min(params->max_match_length, params->nice_match_length) > 65536)
+               return false;
+
+       return true;
+}
+
 const struct compressor_ops lzms_compressor_ops = {
+       .params_valid       = lzms_params_valid,
+       .get_needed_memory  = lzms_get_needed_memory,
        .create_compressor  = lzms_create_compressor,
        .compress           = lzms_compress,
        .free_compressor    = lzms_free_compressor,