Unified compression interfaces

2021-05-05 18:07:12 +02:00
parent ff708230bd
commit c2f8f4c962
10 changed files with 138 additions and 114 deletions
--- a/src/lib/compress.c
+++ b/src/lib/compress.c
@@ -0,0 +1,76 @@
+/**
+ * Necronda Web Server
+ * Compression interface
+ * src/lib/compress.c
+ * Lorenz Stechauner, 2021-05-05
+ */
+
+#include "compress.h"
+#include <malloc.h>
+#include <errno.h>
+
+int compress_init(compress_ctx *ctx, int mode) {
+    ctx->gzip = NULL;
+    ctx->brotli = NULL;
+    int ret;
+    if (mode & COMPRESS_GZ) {
+        ctx->gzip = malloc(sizeof(z_stream));
+        ctx->gzip->zalloc = Z_NULL;
+        ctx->gzip->zfree = Z_NULL;
+        ctx->gzip->opaque = Z_NULL;
+        ret = deflateInit2(ctx->gzip, COMPRESS_LEVEL_GZIP, Z_DEFLATED, 15 + 16, 9, Z_DEFAULT_STRATEGY);
+        if (ret != Z_OK) return -1;
+    }
+    if (mode & COMPRESS_BR) {
+        ctx->brotli = BrotliEncoderCreateInstance(NULL, NULL, NULL);
+        if (ctx->brotli == NULL) return -1;
+        BrotliEncoderSetParameter(ctx->brotli, BROTLI_PARAM_MODE, BROTLI_MODE_GENERIC);
+        BrotliEncoderSetParameter(ctx->brotli, BROTLI_PARAM_QUALITY, COMPRESS_LEVEL_BROTLI);
+    }
+    return 0;
+}
+
+int compress_compress(compress_ctx *ctx, const char *in, unsigned long *in_len, char *out, unsigned long *out_len, int finish) {
+    if ((ctx->mode & COMPRESS_GZ) && (ctx->mode & COMPRESS_BR)) {
+        errno = EINVAL;
+        return -1;
+    }
+    return compress_compress_mode(ctx, ctx->mode, in, in_len, out, out_len, finish);
+}
+
+int compress_compress_mode(compress_ctx *ctx, int mode, const char *in, unsigned long *in_len, char *out, unsigned long *out_len, int finish) {
+    if ((mode & COMPRESS_GZ) && (mode & COMPRESS_BR)) {
+        errno = EINVAL;
+        return -1;
+    } else if (mode & COMPRESS_GZ) {
+        ctx->gzip->next_in = (unsigned char*) in;
+        ctx->gzip->avail_in = *in_len;
+        ctx->gzip->next_out = (unsigned char*) out;
+        ctx->gzip->avail_out = *out_len;
+        int ret = deflate(ctx->gzip, finish ? Z_FINISH : Z_NO_FLUSH);
+        *in_len = ctx->gzip->avail_in;
+        *out_len = ctx->gzip->avail_out;
+        return ret;
+    } else if (mode & COMPRESS_BR) {
+        int ret = BrotliEncoderCompressStream(ctx->brotli, finish ? BROTLI_OPERATION_FINISH : BROTLI_OPERATION_PROCESS,
+                                              in_len, (const unsigned char**) &in, out_len, (unsigned char **) &out, NULL);
+        return (ret == BROTLI_TRUE) ? 0 : -1;
+    } else {
+        errno = EINVAL;
+        return -2;
+    }
+}
+
+int compress_free(compress_ctx *ctx) {
+    if (ctx->gzip != NULL) {
+        deflateEnd(ctx->gzip);
+        free(ctx->gzip);
+        ctx->gzip = NULL;
+    }
+    if (ctx->brotli != NULL) {
+        BrotliEncoderDestroyInstance(ctx->brotli);
+        ctx->brotli = NULL;
+    }
+    ctx->mode = 0;
+    return 0;
+}