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authorDavid Oberhollenzer <david.oberhollenzer@sigma-star.at>2020-09-14 16:17:15 +0200
committerDavid Oberhollenzer <david.oberhollenzer@sigma-star.at>2020-09-16 09:34:35 +0200
commit5f637f97c3427dc6e1a68678aefee1f62ca34d62 (patch)
tree75254191b93adce81e188069d54de383c0123984
parent0a0cbefc6ebb6174aad3e6f0b8a6dea87aed49da (diff)
Implement ostream compressor wrapper
Signed-off-by: David Oberhollenzer <david.oberhollenzer@sigma-star.at>
-rw-r--r--include/fstream.h63
-rw-r--r--lib/fstream/Makemodule.am12
-rw-r--r--lib/fstream/compress/gzip.c81
-rw-r--r--lib/fstream/compress/ostream_compressor.c98
-rw-r--r--lib/fstream/compress/xz.c80
-rw-r--r--lib/fstream/compressor.c47
-rw-r--r--lib/fstream/internal.h27
7 files changed, 408 insertions, 0 deletions
diff --git a/include/fstream.h b/include/fstream.h
index cc562ca..cb992f8 100644
--- a/include/fstream.h
+++ b/include/fstream.h
@@ -55,6 +55,21 @@ enum {
OSTREAM_OPEN_SPARSE = 0x02,
};
+enum {
+ /**
+ * @brief Deflate compressor with gzip headers.
+ *
+ * This actually creates a gzip compatible file, including a
+ * gzip header and trailer.
+ */
+ FSTREAM_COMPRESSOR_GZIP = 1,
+
+ FSTREAM_COMPRESSOR_XZ = 2,
+
+ FSTREAM_COMPRESSOR_MIN = 1,
+ FSTREAM_COMPRESSOR_MAX = 2,
+};
+
#ifdef __cplusplus
extern "C" {
#endif
@@ -109,6 +124,27 @@ SQFS_INTERNAL istream_t *istream_open_file(const char *path);
SQFS_INTERNAL istream_t *istream_open_stdin(void);
/**
+ * @brief Create an output stream that transparently compresses data.
+ *
+ * @memberof ostream_t
+ *
+ * This function creates an output stream that transparently compresses all
+ * data appended to it and writes the compressed data to an underlying, wrapped
+ * output stream.
+ *
+ * The new stream takes ownership of the wrapped stream and destroys it when
+ * the compressor stream is destroyed. If this function fails, the wrapped
+ * stream is also destroyed.
+ *
+ * @param strm A pointer to another stream that should be wrapped.
+ * @param comp_id An identifier describing the compressor to use.
+ *
+ * @return A pointer to an output stream on success, NULL on failure.
+ */
+SQFS_INTERNAL ostream_t *ostream_compressor_create(ostream_t *strm,
+ int comp_id);
+
+/**
* @brief Append a block of data to an output stream.
*
* @memberof ostream_t
@@ -245,6 +281,33 @@ SQFS_INTERNAL sqfs_s32 ostream_append_from_istream(ostream_t *out,
istream_t *in,
sqfs_u32 size);
+/**
+ * @brief Resolve a compressor name to an ID.
+ *
+ * @param name A compressor name.
+ *
+ * @return A compressor ID on success, -1 on failure.
+ */
+SQFS_INTERNAL int fstream_compressor_id_from_name(const char *name);
+
+/**
+ * @brief Resolve a id to a compressor name.
+ *
+ * @param id A compressor ID.
+ *
+ * @return A compressor name on success, NULL on failure.
+ */
+SQFS_INTERNAL const char *fstream_compressor_name_from_id(int id);
+
+/**
+ * @brief Check if support for a given compressor has been built in.
+ *
+ * @param id A compressor ID.
+ *
+ * @return True if the compressor is supported, false if not.
+ */
+SQFS_INTERNAL bool fstream_compressor_exists(int id);
+
#ifdef __cplusplus
}
#endif
diff --git a/lib/fstream/Makemodule.am b/lib/fstream/Makemodule.am
index 27e4701..9178647 100644
--- a/lib/fstream/Makemodule.am
+++ b/lib/fstream/Makemodule.am
@@ -2,6 +2,8 @@ libfstream_a_SOURCES = include/fstream.h
libfstream_a_SOURCES += lib/fstream/internal.h
libfstream_a_SOURCES += lib/fstream/ostream.c lib/fstream/printf.c
libfstream_a_SOURCES += lib/fstream/istream.c
+libfstream_a_SOURCES += lib/fstream/compressor.c
+libfstream_a_SOURCES += lib/fstream/compress/ostream_compressor.c
libfstream_a_CFLAGS = $(AM_CFLAGS) $(ZLIB_CFLAGS) $(XZ_CFLAGS)
libfstream_a_CPPFLAGS = $(AM_CPPFLAGS)
@@ -14,4 +16,14 @@ libfstream_a_SOURCES += lib/fstream/unix/ostream.c
libfstream_a_SOURCES += lib/fstream/unix/istream.c
endif
+if WITH_XZ
+libfstream_a_SOURCES += lib/fstream/compress/xz.c
+libfstream_a_CPPFLAGS += -DWITH_XZ
+endif
+
+if WITH_GZIP
+libfstream_a_SOURCES += lib/fstream/compress/gzip.c
+libfstream_a_CPPFLAGS += -DWITH_GZIP
+endif
+
noinst_LIBRARIES += libfstream.a
diff --git a/lib/fstream/compress/gzip.c b/lib/fstream/compress/gzip.c
new file mode 100644
index 0000000..f604b71
--- /dev/null
+++ b/lib/fstream/compress/gzip.c
@@ -0,0 +1,81 @@
+/* SPDX-License-Identifier: GPL-3.0-or-later */
+/*
+ * gzip.c
+ *
+ * Copyright (C) 2019 David Oberhollenzer <goliath@infraroot.at>
+ */
+#include "../internal.h"
+
+#include <zlib.h>
+
+typedef struct {
+ ostream_comp_t base;
+
+ z_stream strm;
+} ostream_gzip_t;
+
+static int flush_inbuf(ostream_comp_t *base, bool finish)
+{
+ ostream_gzip_t *gzip = (ostream_gzip_t *)base;
+ size_t have;
+ int ret;
+
+ gzip->strm.avail_in = base->inbuf_used;
+ gzip->strm.next_in = base->inbuf;
+
+ do {
+ gzip->strm.avail_out = BUFSZ;
+ gzip->strm.next_out = base->outbuf;
+
+ ret = deflate(&gzip->strm, finish ? Z_FINISH : Z_NO_FLUSH);
+
+ if (ret == Z_STREAM_ERROR) {
+ fprintf(stderr,
+ "%s: internal error in gzip compressor.\n",
+ base->wrapped->get_filename(base->wrapped));
+ return -1;
+ }
+
+ have = BUFSZ - gzip->strm.avail_out;
+
+ if (base->wrapped->append(base->wrapped, base->outbuf, have))
+ return -1;
+ } while (gzip->strm.avail_out == 0);
+
+ base->inbuf_used = 0;
+ return 0;
+}
+
+static void cleanup(ostream_comp_t *base)
+{
+ ostream_gzip_t *gzip = (ostream_gzip_t *)base;
+
+ deflateEnd(&gzip->strm);
+}
+
+ostream_comp_t *ostream_gzip_create(const char *filename)
+{
+ ostream_gzip_t *gzip = calloc(1, sizeof(*gzip));
+ ostream_comp_t *base = (ostream_comp_t *)gzip;
+ int ret;
+
+ if (gzip == NULL) {
+ fprintf(stderr, "%s: creating gzip wrapper: %s.\n",
+ filename, strerror(errno));
+ return NULL;
+ }
+
+ ret = deflateInit2(&gzip->strm, 9, Z_DEFLATED, 16 + 15, 8,
+ Z_DEFAULT_STRATEGY);
+ if (ret != Z_OK) {
+ fprintf(stderr,
+ "%s: internal error creating gzip compressor.\n",
+ filename);
+ free(gzip);
+ return NULL;
+ }
+
+ base->flush_inbuf = flush_inbuf;
+ base->cleanup = cleanup;
+ return base;
+}
diff --git a/lib/fstream/compress/ostream_compressor.c b/lib/fstream/compress/ostream_compressor.c
new file mode 100644
index 0000000..5137f1d
--- /dev/null
+++ b/lib/fstream/compress/ostream_compressor.c
@@ -0,0 +1,98 @@
+/* SPDX-License-Identifier: GPL-3.0-or-later */
+/*
+ * ostream_compressor.c
+ *
+ * Copyright (C) 2019 David Oberhollenzer <goliath@infraroot.at>
+ */
+#include "../internal.h"
+
+static int comp_append(ostream_t *strm, const void *data, size_t size)
+{
+ ostream_comp_t *comp = (ostream_comp_t *)strm;
+ size_t diff;
+
+ while (size > 0) {
+ if (comp->inbuf_used >= BUFSZ) {
+ if (comp->flush_inbuf(comp, false))
+ return -1;
+ }
+
+ diff = BUFSZ - comp->inbuf_used;
+
+ if (diff > size)
+ diff = size;
+
+ memcpy(comp->inbuf + comp->inbuf_used, data, diff);
+
+ comp->inbuf_used += diff;
+ data = (const char *)data + diff;
+ size -= diff;
+ }
+
+ return 0;
+}
+
+static int comp_flush(ostream_t *strm)
+{
+ ostream_comp_t *comp = (ostream_comp_t *)strm;
+
+ if (comp->inbuf_used > 0) {
+ if (comp->flush_inbuf(comp, true))
+ return -1;
+ }
+
+ return comp->wrapped->flush(comp->wrapped);
+}
+
+static const char *comp_get_filename(ostream_t *strm)
+{
+ ostream_comp_t *comp = (ostream_comp_t *)strm;
+
+ return comp->wrapped->get_filename(comp->wrapped);
+}
+
+static void comp_destroy(sqfs_object_t *obj)
+{
+ ostream_comp_t *comp = (ostream_comp_t *)obj;
+
+ comp->cleanup(comp);
+ sqfs_destroy(comp->wrapped);
+ free(comp);
+}
+
+ostream_t *ostream_compressor_create(ostream_t *strm, int comp_id)
+{
+ ostream_comp_t *comp = NULL;
+ sqfs_object_t *obj;
+ ostream_t *base;
+
+ switch (comp_id) {
+ case FSTREAM_COMPRESSOR_GZIP:
+#ifdef WITH_GZIP
+ comp = ostream_gzip_create(strm->get_filename(strm));
+#endif
+ break;
+ case FSTREAM_COMPRESSOR_XZ:
+#ifdef WITH_XZ
+ comp = ostream_xz_create(strm->get_filename(strm));
+#endif
+ break;
+ default:
+ break;
+ }
+
+ if (comp == NULL)
+ return NULL;
+
+ comp->wrapped = strm;
+ comp->inbuf_used = 0;
+
+ base = (ostream_t *)comp;
+ base->append = comp_append;
+ base->flush = comp_flush;
+ base->get_filename = comp_get_filename;
+
+ obj = (sqfs_object_t *)comp;
+ obj->destroy = comp_destroy;
+ return base;
+}
diff --git a/lib/fstream/compress/xz.c b/lib/fstream/compress/xz.c
new file mode 100644
index 0000000..65bda0b
--- /dev/null
+++ b/lib/fstream/compress/xz.c
@@ -0,0 +1,80 @@
+/* SPDX-License-Identifier: GPL-3.0-or-later */
+/*
+ * xz.c
+ *
+ * Copyright (C) 2019 David Oberhollenzer <goliath@infraroot.at>
+ */
+#include "../internal.h"
+
+#include <lzma.h>
+
+typedef struct {
+ ostream_comp_t base;
+
+ lzma_stream strm;
+} ostream_xz_t;
+
+static int flush_inbuf(ostream_comp_t *base, bool finish)
+{
+ ostream_xz_t *xz = (ostream_xz_t *)base;
+ lzma_ret ret_xz;
+ size_t have;
+
+ xz->strm.next_in = base->inbuf;
+ xz->strm.avail_in = base->inbuf_used;
+
+ do {
+ xz->strm.next_out = base->outbuf;
+ xz->strm.avail_out = BUFSZ;
+
+ ret_xz = lzma_code(&xz->strm, finish ? LZMA_FINISH : LZMA_RUN);
+
+ if ((ret_xz != LZMA_OK) && (ret_xz != LZMA_STREAM_END)) {
+ fprintf(stderr,
+ "%s: internal error in XZ compressor.\n",
+ base->wrapped->get_filename(base->wrapped));
+ return -1;
+ }
+
+ have = BUFSZ - xz->strm.avail_out;
+
+ if (base->wrapped->append(base->wrapped, base->outbuf, have))
+ return -1;
+ } while (xz->strm.avail_out == 0);
+
+ base->inbuf_used = 0;
+ return 0;
+}
+
+static void cleanup(ostream_comp_t *base)
+{
+ ostream_xz_t *xz = (ostream_xz_t *)base;
+
+ lzma_end(&xz->strm);
+}
+
+ostream_comp_t *ostream_xz_create(const char *filename)
+{
+ ostream_xz_t *xz = calloc(1, sizeof(*xz));
+ ostream_comp_t *base = (ostream_comp_t *)xz;
+ lzma_ret ret_xz;
+
+ if (xz == NULL) {
+ fprintf(stderr, "%s: creating xz wrapper: %s.\n",
+ filename, strerror(errno));
+ return NULL;
+ }
+
+ ret_xz = lzma_easy_encoder(&xz->strm, LZMA_PRESET_DEFAULT,
+ LZMA_CHECK_CRC64);
+ if (ret_xz != LZMA_OK) {
+ fprintf(stderr, "%s: error initializing XZ compressor\n",
+ filename);
+ free(xz);
+ return NULL;
+ }
+
+ base->flush_inbuf = flush_inbuf;
+ base->cleanup = cleanup;
+ return base;
+}
diff --git a/lib/fstream/compressor.c b/lib/fstream/compressor.c
new file mode 100644
index 0000000..b8f9c6b
--- /dev/null
+++ b/lib/fstream/compressor.c
@@ -0,0 +1,47 @@
+/* SPDX-License-Identifier: GPL-3.0-or-later */
+/*
+ * compressor.c
+ *
+ * Copyright (C) 2019 David Oberhollenzer <goliath@infraroot.at>
+ */
+#include "internal.h"
+
+int fstream_compressor_id_from_name(const char *name)
+{
+ if (strcmp(name, "gzip") == 0)
+ return FSTREAM_COMPRESSOR_GZIP;
+
+ if (strcmp(name, "xz") == 0)
+ return FSTREAM_COMPRESSOR_XZ;
+
+ return -1;
+}
+
+const char *fstream_compressor_name_from_id(int id)
+{
+ if (id == FSTREAM_COMPRESSOR_GZIP)
+ return "gzip";
+
+ if (id == FSTREAM_COMPRESSOR_XZ)
+ return "xz";
+
+ return NULL;
+}
+
+bool fstream_compressor_exists(int id)
+{
+ switch (id) {
+#ifdef WITH_GZIP
+ case FSTREAM_COMPRESSOR_GZIP:
+ return true;
+#endif
+#ifdef WITH_XZ
+ case FSTREAM_COMPRESSOR_XZ:
+ return true;
+#endif
+ default:
+ break;
+ }
+
+ return false;
+}
diff --git a/lib/fstream/internal.h b/lib/fstream/internal.h
index e8b0c07..ae6a29a 100644
--- a/lib/fstream/internal.h
+++ b/lib/fstream/internal.h
@@ -22,4 +22,31 @@
#define BUFSZ (262144)
+typedef struct ostream_comp_t {
+ ostream_t base;
+
+ ostream_t *wrapped;
+
+ size_t inbuf_used;
+
+ sqfs_u8 inbuf[BUFSZ];
+ sqfs_u8 outbuf[BUFSZ];
+
+ int (*flush_inbuf)(struct ostream_comp_t *ostrm, bool finish);
+
+ void (*cleanup)(struct ostream_comp_t *ostrm);
+} ostream_comp_t;
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+SQFS_INTERNAL ostream_comp_t *ostream_gzip_create(const char *filename);
+
+SQFS_INTERNAL ostream_comp_t *ostream_xz_create(const char *filename);
+
+#ifdef __cplusplus
+}
+#endif
+
#endif /* INTERNAL_H */