From 72cb710c08c4617fa491fe4824c4f99d3d3402fb Mon Sep 17 00:00:00 2001 From: Tomas Vondra Date: Mon, 13 Mar 2023 20:42:33 +0100 Subject: [PATCH 4/4] comment improvements --- src/bin/pg_dump/compress_lz4.c | 22 +++++++++++++++++----- 1 file changed, 17 insertions(+), 5 deletions(-) diff --git a/src/bin/pg_dump/compress_lz4.c b/src/bin/pg_dump/compress_lz4.c index 94f28d6806..19a9cf2df2 100644 --- a/src/bin/pg_dump/compress_lz4.c +++ b/src/bin/pg_dump/compress_lz4.c @@ -190,10 +190,15 @@ LZ4File_get_error(CompressFileHandle *CFH) } /* - * Prepare an already alloc'ed LZ4File struct for subsequent calls. + * Prepare an already alloc'ed LZ4File struct for subsequent calls (either + * compression or decompression). * - * It creates the necessary contexts for the operations. When compressing, - * it additionally writes the LZ4 header in the output stream. + * It creates the necessary contexts for the operations. When compressing data + * (indicated by compressing=true), it additionally writes the LZ4 header in the + * output stream. + * + * Returns 0 on success. In case of a failure returns 1, and stores the error + * code in fs->errcode. */ static int LZ4File_init(LZ4File *fs, int size, bool compressing) @@ -206,6 +211,7 @@ LZ4File_init(LZ4File *fs, int size, bool compressing) fs->compressing = compressing; fs->inited = true; + /* When compressing, write LZ4 header to the output stream. */ if (fs->compressing) { fs->buflen = LZ4F_compressBound(LZ4_IN_SIZE, &fs->prefs); @@ -248,7 +254,7 @@ LZ4File_init(LZ4File *fs, int size, bool compressing) return 1; } - fs->buflen = size > LZ4_OUT_SIZE ? size : LZ4_OUT_SIZE; + fs->buflen = (size > LZ4_OUT_SIZE) ? size : LZ4_OUT_SIZE; fs->buffer = pg_malloc(fs->buflen); fs->overflowalloclen = fs->buflen; @@ -262,7 +268,10 @@ LZ4File_init(LZ4File *fs, int size, bool compressing) /* * Read already decompressed content from the overflow buffer into 'ptr' up to * 'size' bytes, if available. If the eol_flag is set, then stop at the first - * occurrence of the new line char prior to 'size' bytes. + * occurrence of the newline char prior to 'size' bytes. + * + * Returns the number of bytes read from the overflow buffer (and copied into + * the 'ptr' buffer), or 0 if the overflow buffer is empty. * * Any unread content in the overflow buffer is moved to the beginning. */ @@ -304,6 +313,9 @@ LZ4File_read_overflow(LZ4File *fs, void *ptr, int size, bool eol_flag) * at an overflow buffer within LZ4File. Of course, when the function is * called, it will first try to consume any decompressed content already * present in the overflow buffer, before decompressing new content. + * + * Returns the number of bytes of decompressed data copied into the ptr + * buffer, or -1 in case of error. */ static int LZ4File_read_internal(LZ4File *fs, void *ptr, int ptrsize, bool eol_flag) -- 2.39.2